# Do people who deny evolution know less about it than others?

July 8, 2014 • 7:20 am

Several people sent me a short essay in the New York Times, “When beliefs and facts collide,” by Brendan Nyhan.  They thought, correctly, that I’d be interested in it because it discusses the reasons why so many Americans deny palpably true science, in particular evolution and human-caused global warming. Both of these “theories” are supported by mountains of evidence (no rational scientist would deny evolution, and something like 97% of climate scientists also accept that human activities are making the Earth warmer).

So why the opposition from many Americans? Nyhan summarizes the answers briefly, but they all come from a 49-page paper by Dan M. Kahan that’s in press in Advances in Political Psychology. Kahan is a professor of law and psychology at Yale. The paper, in advance form, can be downloaded free at the link at bottom.

The title refers only to climate science, but a large chunk of the paper is about evolution, and I’ll deal with that today. Tomorrow, I hope, I’ll discuss Kahan’s conclusions about climate science.

Kahan first cites previous studies that seem to show that those who reject evolution—42% of Americans are young-earth creationists when it comes to humans, while only 19% accept purely naturalistic evolution—know just as much about evolution as those who accept it.  Then Kahan proceeds to show pretty much the same thing, but adds something else: something most of us know, but others either don’t know or don’t get.  And that is that those who reject evolution do so largely on religious grounds, not because they don’t know what evolution is. In other words, Kahan concludes that American rejection of evolution is not due to lack of information or ignorance; it’s due to adherence to one’s faith community that rejects evolution. You reject evolution because your “community” does, and you want to get along with them.  Tomorrow I’ll show that this is pretty much true for global-warming denialism as well, but the “communities” there are ones of political conservatism or liberalism, not religion.

Anyway, Kahan gave a test of science knowledge (“Ordinary science intelligence,” or OSI) to a number of people, and also measured their religiosity as “self-reported church attendance, frequency of prayer, and perceived importance of god in one’s life.” To be sure, it’s not clear from the paper whether Kahan did the polling himself or is simply using other peoples’ data. But no matter.

You might want to take the OSI test itself, as it’s shown at the end of the paper. Some of the items are easy, like the following (the percentage of correct answers and references are also given):

And others are harder, like these. The first one was the hardest for the takers, and it is a stumper. I got it, but had to think carefully. The third one you can solve in your head intuitively or with a simple algebra equation, but only 13% of people got it; most people answer “ten cents.”

And the other about your knowledge of what the theory of evolution maintains:

Notice that 55% of Americans agreed with evolution (a bit higher than that found in the Gallup Survey, but still disconcertingly low), but 81% of Americans at least know what the theory says. That’s still pretty low to me; how can one not know what biological evolution is?

At any rate, Kahan simply looked at how peoples’ performance on the evolution questions correlated with their general scientific knowledge as shown by their OSI score. First he showed that for the non-evolution science questions, performance on them was pretty highly correlated with overall performance.

The three graphs below show that for three of the “non-evolution” science questions, performance on those questions was well correlated with overall OSI. The relationship was not as tight for the tough mammography question, for only those who had the best scientific knowledge or probability skills could answer it correctly. These graphs show, for each category of OSI performance (X axis), what percentage of people answered the question shown correctly (Y axis). Scores on OSI were placed into 21 discrete categories, and bars are the 95% confidence intervals:

Evolution wasn’t quite the same, as acceptance of it didn’t rise as strongly with general performance on OSI:

In other words, the better you did overall, the higher your probability of accepting evolution, but that probability didn’t rise as fast with general science intelligence as did correct knowledge of other scientific ideas. Why is that?

If you break down the data by religious belief of people in each of the 21 categories, you find something interesting. Religious belief doesn’t make much of a difference in non-evolution questions, as seen by the yellow scores (of those more religious than average) versus blue scores (of those less religious than average). For example, look at the three non-evolution questions whose overall results are given above:

Religious people’s scores are pretty much in line with less religious people’s: the orange bars highly overlap the blue ones.

Now look at the evolution question:

The results are clear: in contrast to other scientific facts, even if you know more about science in general (X axis), if you’re pretty religious (orange bars), it doesn’t affect your likelihood of accepting evolution.  It does, however, if you’re less religious (blue bars). The combination of these two plots is what flattens the summary plot for this question given above.

While the authors found a slightly negative correlation between religion and OSI (-0.17), meaning that religious people don’t know quite as much about science in general as do the nonreligious, that can’t explain these results, for we are comparing performance on a single question within a group of people comprising both religious and less religious people who know the same amount about science.. The discrepancy is large; as the authors note (my emphasis):

Their performance on the Evolution item, however, is clearly discrepant. One might conclude that Evolution is validly measuring science comprehension for non-religious test takers, although in that case it is a very easy question: the likelihood a nonreligious individual with a mean OSI score will get the “right” answer is 80%—even higher than the likelihood that this person would respond correctly to the relatively simple Electron item.

it is a very easy question: the likelihood a nonreligious individual with a mean OSI score will get the “right” answer is 80%—even higher than the likelihood that this person would respond correctly to the relatively simple Electron item.

In contrast, for a relatively religious individual with a mean OSI score, the probability of giving the correct response is around 30%. This 50 percentage-point differential tells us that Evolution does not have the same relationship to the latent OSI disposition in these two groups.

Indeed, it is obvious that Evolution has no relation to OSI whatsoever in relatively religious re-spondents. For such individuals, the predicted probability of giving the correct answer does not increase as individuals display a higher degree of science comprehension. On the contrary, it trends slightly downward, suggesting that religious individuals highest in OSI are even more likely to get the question “wrong.”

Well, do religious people simply know less about what the theory of evolution says than do other people, and that explains the discrepancy above? If so, then the lower acceptance of the theory among the religious (at every degree of OSI performance) could simply be due to their ignorance. (I mean ignorance about evolution, of course, not general ignorance.)

But that’s not the case. Below you can see the performance on the “I accept evolution” question divided up by OSI score, with and without religious belief indicated. Total data on the left, divided up by degree of religiosity on the right:

While religious people know slightly less about the theory, especially at higher levels of general science intelligence, both curves on the right go up with OSI score, and resemble curves for other individual questions on the OSI exam. As the authors note:

When the clause, “[a]ccording to the theory of evolution . . .” introduces the proposition “human beings, as we know them today, developed from earlier species of animals” (NSF 2006, 2014), the discrepancy between relatively religious and relatively non-religious test-takers disappears! Freed from having to choose between conveying what they understand to be the position of science and making a profession of “belief” that denigrates their identities, religious test-takers of varying levels of OSI now respond very closely to how nonreligious ones of corresponding OSI levels do. The profile of the item response curve—a positive slope in relation to OSI for both groups—supports the inference that answering this variant of Evolution correctly occupies the same relation to OSI as do the other items in the scale. However, this particular member of the scale turns out to be even easier—even less diagnostic of anything other than a dismally low comprehension level in those who get it wrong—than the simple NSF Indicator Electron item.

The take-home lesson: even science-savvy religious people don’t accept the truth of evolution, though they accept the truth of virtually every other scientific concept.  In other words, they uniquely reject evolution because of their religious beliefs. That rejection, to repeat, is not based on ignorance, for at all levels of OSI performance the religious know nearly as much about what evolution says as do the nonreligious. (This is borne out by previous work that asked even more about the theory of evolution.)

As I’ve been saying repeatedly, the way to eliminate creationism is not to teach people about evolution (as I tried to do in WEIT), but to get rid of the major factor that make them deny evolution: religion. Granted, WEIT was successful in changing some people’s minds (I have lots of emails attesting to that), but I suspect its main effect was simply to tell people who already accepted evolution about the kind and amount of evidence supporting it.

If we want to eliminate creationism, we have to eliminate the kind of religious belief that makes people reject evolution. (That, of course, is not all religious belief: Unitarian Universalists, I suspect, have no problem with evolution.) But to eliminate religious belief, we must eliminate the conditions that promote it, which in my opinion are dysfunctional aspects of society that make people turn to God. But that’s another theory, and one I’ve written about before.

Tomorrow we’ll compare evolution denialism to climate-change denialism.

h/t: Wendy

_________

Kahan, D. M. 2014 (in press). Climate science commuication and the measurement problem.  Adv. Pol. Psych.

## 162 thoughts on “Do people who deny evolution know less about it than others?”

1. I know we disagree on this one, but still think it worth discussing here.

People are very reluctant to give up their religious identity (and identity here is probably deeper seated than any particular belief). So how about the strategy – accommodationism properly so called – of arguing that evolution is compatible with their religion? FWIW, I can with a clear conscience argue that the problems facing an evolution-accepting believer are no greater than, and probably far smaller than, those facing a believer who denies evolution, since denial leaves God with fewer excuses; and I can point as you know to numerous intelligent and articulate believers who would share this conclusion.

1. Jesper Both Pedersen says:

But the problem is that it is a superficial and dishonest acceptance of religion according to many believers.

I mean how are we going to preach to them that evolution is compatible with their religion if only they cange their literal understanding of the faith to a metaphorical one?

If facts won’t make them change their minds, then why should an obvious lie?

2. mecwordpress says:

From my perspective the problem with accommodation – “arguing that evolution is compatible with their religion” is that it isn’t. I do not think the interests of anyone are furthered by arguing a position that isn’t true.

1. Or at least by infantalizing someone by suggesting that they cannot decide themselves how to fit things together. That’s what science is about, after all. People coming to misinformed conclusions is unfortunately an expected by product.

3. Diana MacPherson says:

I think Jerry has the right answer. Sure accommodationist approaches may get small numbers converted but I doubt it really will given all the failed efforts of Biologos etc. the real way to create a big disruption is to eliminate the conditions that lead to religiosity: poverty, corruption, anything that leads individuals to feel unsafe and powerless to change their lot in life.

4. GBJames says:

It would be nice, I suppose, but the track record for accommodation says you’re wasting your time.

5. Sastra says:

People are very reluctant to give up their religious identity (and identity here is probably deeper seated than any particular belief).

So how about this strategy: let’s assume these religious ‘people’ are grown-ups, just like us, and that they are at least somewhat capable of engaging with the idea that what is personally useful or fulfilling is not necessarily true. Like us, they can distinguish between the reasonable practices of their church and the dogmatic beliefs. And that they can change their mind about their religion … and still be the same basic person they were before! They don’t die! The world doesn’t end!
It doesn’t even get all horrible for everyone everywhere forever! They don’t even have to give up their community — if this gets around.

The Little People Argument (“But they can’t handle the truth! They don’t even care about truth! Not like us!”) only sounds accomodating, practical, and pragmatic if it’s not spelled out too clearly and/or the Little People really are that different than us brave, wise atheists.

I suspect that in the long run it will be better and easier to lessen the grip of the idea that faith = identity than it would be to play a never-ending game of whack-a-mole as we keep trying to bop the wee folk into nicer religious-identity holes. The moles play according to the rules of Calvinball.

6. Kevin says:

Evolution and private Deism. The God of Nothing can accommodate anything, but Theism is, by definition, off the mark.

7. Scote says:

“So how about the strategy – accommodationism properly so called – of arguing that evolution is compatible with their religion? “

Who are scientists to say what is compatible with someone’s religion? Who are the religious going to listen to on such a conflict? A scientist? Or their priests?

That just isn’t a tenable track to go down in the US, as Karl Giberson discovered.

1. Shrewd point. But anyone, including a godless scientist, can point out that their priests, if they are Catholic, Episcopalian, or numerous others (including mainstream Scottish Presbyterians) DO accept the fact of evolution.

1. GBJames says:

Not really. They accept a weirdly modified version of the theory that includes spirits and magic.

1. Larry Cook says:

My understanding from my education in Catholic schools and information I’ve read recently is that the Catholic church does indeed accept evolution without any modification.

1. Gregory Kusnick says:

The Church does not accept that humans are an unplanned byproduct of a purposeless natural process, which is what the unmodified theory implies.

2. GBJames says:

The Church holds to a “eat your cake and have it too” version of evolution. They say (at least some of them say) that they accept evolution without modification, but then they go ahead and modify it by insisting that Adam and Eve were real, that their sky god interferes in physical processes and suspends the laws of physics from time to time, that you can pray to specially designated dead people who will modify reality for you, and so forth. All of this magic is inconsistent and incompatible with the theory of evolution and science in general.

8. The problem with accomodationism, from my reductionist viewpoint (I love reduction), is that it prioritizes strategy over honesty. Which is icky.

Also, you have to keep the endgame in mind. Wouldn’t it be great if humans could get to a point where everyone saw religions for the myths they are, and could finally see that faith (in the religious sense) is actually a vice? The theory of evolution is one tool that chips away at religious faith. Why would we want to blunt it?

9. The real goal is not particularly to get religious people to accept evolution, but to be more rational in ALL of their decisions that impact the rest of us.

10. reasonshark says:

Even assuming that the tactic is effective at creating broader acceptance of evolutionary theory – and given how explicitly accommodationist organisations like BioLogos spend more time fussing over religious doctrines than actually teaching evolution, I doubt it is – it would simply trade in one intellectual problem for another. That is, you trade in poor acceptance of evolution and get failure to remove faith-based thinking because you coddled it.

Intuitively, it sounds better to reconcile both sides than to have them butt heads in a contest, but in intellectual discussion, that presupposes that both sides have at least one good point worth salvaging, and the religious denialists simply don’t. In any case, the evidence provided by the OP suggests that the way to increase acceptance of evolution would not be to weaken evolution’s explanatory power, but to strongly minimize religious belief and practice.

I’m with Jason Rosenhouse here: ad science says that telling your message forthright is _very_ effective.

Evolution is a fact. Religion lies about facts.

Live with it.

12. H.H. says:

So how about the strategy – accommodationism properly so called – of arguing that evolution is compatible with their religion?

The reason that’s a losing strategy is because evolution isn’t compatible with their religion.

2. GM says:

I am amazed that fully 8% answered the breast cancer question correctly. That’s actually quite high.

But others actually paint a much worse picture than the raw numbers suggest. Because when you have multiple choice questions, you have to evaluate the replies against the null hypothesis, which is that people just randomly guessed. And by random guessing you are going to get it right 50% of the time when you have 2 options, and 25% of the time when you have 4 options. And the question about the most prevalent gas in Earth’s atmosphere had 4 options and 25% correct answers… In this case, this is not because nobody knew the answer and everyone answered by random guessing, it is because many people “know” the wrong answer, but the general point remains. When you get 65% correct answers on T/F questions, you can only claim that at least 30% (100 – 2*35) of people know the answer but not that 65% do, because you cannot reject the explanation that as many people as those who got it wrong, got it right because of random guessing, not because of knowing the answer.

1. I see your point. Perhaps the test should include an ‘I do not know’ choice, even for T/F questions. Of course some people who do not know will still think they know….

1. I need an “I do not know” option. For the life of me I can’t figure out how the ball doesn’t cost 10 cents. I know it’s algebraic and I’m not applying the correct formula, but solving for x leads me to 10 cents every time. I’m considering a law suit against all of my math and science teachers and the Florida Dept. of Education.

1. the formula is:

x + (1.00 + x) = 1.10

where x = price of ball

so

price of ball + price of bat = $1.10 and price of bat is 1.00 more than price of ball. Solving, you get 1.00 + 2x = 1.10 x = 0.05 or 5 cents. 1. Dominic says: I think I must have done some algebra but really cannot recall – for me I just needed to see the word ‘more’! Algebra is a language I should learn – if only I had time! 1. I had some kind of mental block about algebra all through school, and Jerry’s simple example above still makes no sense to me. I do fine with arithmetic, statistics, geometry, and even the part of calculus that doesn’t involve algebra…but break out the alphabet soup and I turn into a moron. I’m “not neurotypical” anyway, but clearly the wiring in the algebra part of my brain is not up to code. 2. George Martin says: There is a “trivial”, brute force way to solve that also: 1.00 + 0.10 NOPE 1.01 + 0.09 NOPE etc. 3. Diana MacPherson says: Algebra, this is no place for you! – The Little Rascals & a quote I said every time we had to do algebra in elementary school. 2. Even if you can’t hit on the correct equation, you can eliminate the ball costing .10 simply by trying it: .10 + 1.10 = 1.20. (If the bat is a dollar more than the ball, the bat would be 1.10) 1. Jesper Both Pedersen says: That was how I did it, trial and error. Intuitively had it at 10, but then added it up and doh…of course. Math and me will never make it big I’m afraid. 🙂 1. Diana MacPherson says: Estimation and surrounding myself with mathy people is my coping strategy. 1. Jesper Both Pedersen says: Brilliant. I’ll have to try that. 3. Kiwi Dave says: Bob, alternatively to Jerry’s single equation, you could use simultaneous equations. Bat plus ball equals 110 cents Bat minus ball equals 100 cents Add equations. Two bats and no ball equal 210, so one bat equals 105 cents. The real mystery with this problem is where can you buy a bat and ball for$1.10?

4. Diana MacPherson says:

The wording on that one tripped me up. People I asked to explain it found me frustrating. 🙂

5. I’m sorry. I too was a product of the FL education system. Fortunately, I had a good mind for math and the woeful state of affairs there didn’t hinder me. The woeful state of affairs did, however, bore me to death throughout my primary education years. Unfortunately, evolution isn’t as intuitive as math and my creationist biology teacher didn’t help me there. Thank Ceiling Cat for people like Jerry!

2. Scote says:

“I am amazed that fully 8% answered the breast cancer question correctly. That’s actually quite high.”

Surely there must be some standardized way to indicate the expected chance responses in the chart? It seems like a bad idea not to have something like that, given, as you point out that a TF answer would still give a 50% correct result for random guessing.

1. GM says:

It’s not that easy, because as I mentioned, there are also the people who “know” the wrong answers. So the simple model where everyone who answered incorrectly did so because they randomly guessed is not valid. We’re dealing both with plain ignorance and active misinformation, unforutnately

1. Zetopan says:

There is still additional information to be gained from having an “I don’t know” option available, and that is you can separate the
answer not known group from the wrong answer group. I suspect that having the “I don’t know” option would result in a lot of hits to that group.

2. eric says:

It would be difficult to try and derive from theory what the % chance of a specific response to the dollar question or breast cancer question would be, like we can for a T/F or multiple choice question. Though once you’ve given these tests several times and have some results back, you can probably tabulate what the most likely answers are and in what ratios they have occurred on past tests.

3. Timothy Hughbanks says:

I actually thought that it was going to be a very hard question, but most of the heavy lifting is done for the reader in the way the question was worded. A more normal wording of the text’s characteristics would have said, “For women who have a tumor, the test 10% are missed by the test, for women who don’t really have the tumor, 10% are incorrectly told that they do.” I’m not surprised, but given the wording of the question, only 8% correct responses is discouraging, I think.

1. Timothy Hughbanks says:

Well, a normal wording would have been proof-read! Anyway, a more challenging way to word the entire question:

“Of women who are like your friend who have mammograms, 10% have breast tumors. For women who have a tumor, 10% are missed by the test, for women who don’t have the tumor, 10% are incorrectly told that they do.”

1. An even more challenging way to word the question would have mentioned only the prevalence of disease and the sensitivity and specificity of the test. If you get that one, you’re ready to take Step One of the United States Medical Licensing Exam.

4. You have an implicit assumption in there about how many people actually guess, namely that 70% of people guess.

If we expect 50% of people to get the question right when they guess, we have this formula: Total percentage correct = .5n + x, where n = percentage of people who guess and x = percentage who get it right and don’t guess (The .5 being the probability of guessing right).

Plug in percent correct and n as you please and solve for x. In your example, we have 65% = .5(70) + x. x = 65% – 35% = 30%.

You can also see the equation you wrote is actually solving for the number of people who would guess if all the people who didn’t guess got it right. This is the upper bound on the number of people who guess based on the expected distribution. The lower bound is 0 and we’d have .5(0) + x = 65%. Thus x = 65% (the case where no one guessed but everyone “knew” the answer, just that 35% were wrong about what they “knew”).

What all this really means is that we have a range of 30-65% of people who actually know the answer. We have no way of telling how many people guessed, nor do we have any way of deciphering another option–that people made educated guesses while being somewhat sure of the answer based on other knowledge. In that case, we could end up with 65% getting it right but no one having been absolutely sure about it. To determine this, some more in depth questions need to be asked such as asking people to explain their answers.

3. I also wonder how the relationship between evolution reection and religiosity plays out in other countries. My expectation is that it would be stronger in largely Muslim countries, weaker in Europe, and weaker where religion ois less evangelical. After all, the Vatican accepts (after a fashion) the material fact of evolution, even though it seems to require a mysterious intervention for ensoulment somewhere nt he process.

But “the material fact” includes the mechanisms. I think you mean that they accept the existence (outcomes) of the process, but not the process as such.

Also, they do reject the existence, in that a random animals (humans) are taken to be exempt re the existence of evolution, denies the observed bottleneck population re the existence of evolution, et cetera.

Evolution is a fact. Religion lies about facts.

Simple as that.

4. Curt Cameron says:

That’s really an excellent use of graphs to illustrate the point. The idea would be difficult to get if the graphs weren’t constructed so well.

5. gluonspring says:

I think one thing that strikes me about this is the difference between being aware of scientific assertions and having any real understanding of the science. Although people are aware of many scientific assertions most have no real understanding of the science the assertions arise from. Although people accept that electrons are smaller than atoms I seriously doubt that most have the faintest idea how we know that is true, or much of anything about electrons beyond a few simple assertions like this (they are involved in electricity, say). So if some political or religious reason arose for denying this very solid fact, they would not hesitate to deny it because, to them, it is just one of a collection of unrelated assertions about the world and they know that sometimes scientists are actually wrong, so, why not about this they wish them to be wrong about? That is, I’d say that despite people’s ability to answer the True/False evolution question correctly, only a very very tiny fraction of the public understands even the basic idea of natural selection, much less the evidence behind this idea, and that is what makes them extra vulnerable to their religion motivated reasoning.

1. Gregory Kusnick says:

Actually, I take issue with the “very solid fact” that electrons are smaller than atoms.

Atoms have fairly definite size as measured in terms of electron orbitals and covalent bond distances.

With electrons it’s far less clear. The Standard Model tells us there is no hard nugget of electron-stuff with a measurable radius; it’s fields all the way down. And in the case of the electron, those fields (electric and gravitational) have infinite range.

So I’d argue that people who answer in the affirmative (that electrons are smaller than atoms) are not even wrong; they’re trying to compare sizes of things for which the concept of size makes no sense.

1. A couple of things I hope you’ll clear up, GK. Is the field that is electron stuff something that surrounds the atom nucleus — I’m picturing an atom here as a ball-shaped nucleus within a cloud, as if the electron field is sprayed with dye or something to make it visible? Second, does any nucleus’s electron “cloud”, on account of being a field that is perhaps infinite, mingle(?) with electron fields from the nuclei of loads and loads of other atoms?

1. Gregory Kusnick says:

The fields I’m referring to are the electron’s own electrical and gravitational fields. Electrons are considered to be point charges and point masses, i.e. there’s no inner structure to them, just the fields. This is true for isolated free electrons as well as those bound in atoms.

That said, electron orbitals (the places where electrons are likely to be found around atoms) do form a cloud that is in principle infinite in extent (albeit with vanishingly small probability at large distances). This does have observable effects on other atoms; for instance, what makes metals efficient conductors of electricity is the fact that the orbitals of adjacent atoms overlap strongly, forming in effect highways of high probability along which electrons can move freely.

1. Thanks. The little model of an atom I remember from drawings I saw back in school daze did not convey this.

6. gluonspring says:

The breast cancer question is a basic Bayesian probability question, easy to solve with Bayes rule. People’s intuitions suck on these kinds of problems. It does illustrate the idea of a “prior”, which another reader asked me about a few articles ago. The test is your experimental evidence, the background rate of the disease is your prior, it’s what you expect to see before you do the test. The test updates your prior to give you a posterior probability. I raised the idea of priors in relation to the question of how surprising the universe is. Our observations of the universe are like the test. My claim is that we know nothing about the priors, about the background rate of universes of different sorts (or even if that is a meaningful idea), so it is useless to talk about how surprised we should be to see a universe like we do.

1. Curt Cameron says:

But you don’t need to be able to manipulate Bayes’ theorem to get this one right, you just need to be able to pick out the important data and not be distracted by the superfluous stuff. In this case, out of 100 women who were just like your friend, nine of them who tested positive did have cancer, and nine of them who tested positive did not have cancer. If you throw out the superfluous stuff before asking the question, many more would get it right.

So I don’t think this question tested knowledge of conditional probability as much as plain critical thinking skills.

By the way, where are the correct answers? I think I got them all right, but it’s always nice to know for sure!

1. Curt Cameron says:

By the way, I liked the “WIDGET” question about five machines taking five minutes to make five widgets – it’s the same form as the old classic “if it takes a hen and a half a day and a half to lay an egg and a half…” puzzle.

1. Jeff Lewis says:

My first thought on the widget question was that it would depend on whether the 5 machines were an assembly line, or if each of them completed the whole process individually. After just a bit more reflection, I realized it made no difference to the question. It would be important, though, if you wanted to know how long it took to produce widgets in increments other than 100, or how many widgets could be completed in intervals other than 5 minutes.

2. Kevin says:

I agree. Questions like that are not sensitive to the fact that people can easily lose concentration while sipping their coffee and thinking, “This is a boring question…I can’t be bothered to work it out, even though I know (I can work out) the answer.” Then a guess might turn out wrong the proclamation that that specific person did not know the answer is simply incorrect.

1. Scote says:

““This is a boring question…I can’t be bothered to work it out, even though I know (I can work out) the answer.” Then a guess might turn out wrong the proclamation that that specific person did not know the answer is simply incorrect.”

Actually, that is exactly what that kind of question tests, a person’s tendency to use intuitive fast thinking rather than analytical slow thinking. It is less a test of your math skill than of your tendency to jump to conclusions out of lazy thinking.

1. darrelle says:

For testing in this context, surveying a randomly selected sample of people, an added complication is how much people decide they want to invest in the test. Some people are going to breeze over more involved questions not necessarily because of lazy thinking but because they have no incentive / desire to invest the time and effort to make a serious attempt at it.

So I would submit that, to a certain degree, these kinds of questions are testing the level of investment.

1. John Scanlon, FCD says:

And is that a good or bad proxy for scientific understanding?

1. darrelle says:

I think it sucks as a proxy for scientific understanding. I think it is yet another complication that is hard to control for in survey tests like this, and that it degrades the level of confidence that is warranted in the results and the conclusions drawn from them.

3. eric says:

Hard to say, because the real question came with a table that we don’t have, but presumably showing the TPs, FPs, TNs, and FNs. For the people taking that test, having that table sitting in front of them should have put it back into the “thinking” question category rather than the “how do I figure out what to pay attention to” question category.

4. Timothy Hughbanks says:

You’re right. The question is the most “interesting” of all the questions, but the wording of the question gives big hints. By spelling things out for the reader, the reader merely has carefully read and reflect before concluding that 18 women are going to test positive and only 9 of them will actually have a tumor.

5. I don’t remember Bayesian formulas off the top of my head, but I think you just reworked it; I.e the formula could be rewritten the way you describe. I did 9/10 * 1/10 / (9/10 * 1/10 + 1/10 * 9/10) and multiplied by 100 all the way through to get 9(9 + 9) = 50%. Conversely a false negative would be 1/82 if our thinking is right.

2. Latverian Diplomat says:

Yes, and no. The numbers used in the question make it pretty easy to figure out that the number of false positives and true positives is equal. That’s all it takes. I suspect that seeing the data in table form makes this even more intuitive.

On the other hand, the ball and bat question has numbers chosen to make intuition misleading, and setting up an equation is the way to go. Making hard questions “easy” and easy questions “hard” is not good test design in my opinion.

I admit that both of these questions are harder than the basic science fact questions.

At first glance, this test seems to be a pretty poor assessment of science knowledge, in my opinion. Good math skills and good test taking skills seem to me to be very beneficial on the sample questions.

I would have preferred questions that tested student’s incorporation of evolution and the age of the earth without asking about those directly. Questions like “why does Australia have so many more marsupials than other parts of the world?” or “Why is coal found in sedimentary rocks and not igneous rocks?” In multiple choice form of course, but you get the idea.

Because it’s one thing to be aware of a theory you disdain, it’s another to apply it and incorporate into how you think about the world.

3. Wait, doesn’t Pruss know the priors. I mean, you don’t need actual data to use Bayes’ theorem, just data-y feelings.

7. I didn’t see answers to the questions, but is the breast cancer answer 50%?

true positives (9)/total population of positives (18) = .5

1. GM says:

It is 0.5 but the formula in this case is the following:

$P(BreastCancer|PositiveTest) = \cfrac{P(PositiveTest|BreastCancer)P(BreastCancer)}{P(PositiveTest|BreastCancer)P(BreastCancer) + P(PositiveTest|Healthy)P(Healthy)} = \cfrac{0.9*0.1}{(0.9*0.1 + 0.1*0.9)}$

1. Curt Cameron says:

blitz442’s formula was also correct and much more straightforward and intuitive (read: preferred).

1. Thanks Curt, and I like my approach for speed in solving these problems, but I appreciate GM’s contribution as well. It shows the fundamental probability logic, and might be less cumbersome when dealing with very large populations.

That’s why I come to this oasis of learning!

2. GM says:

Why be simple when you can be complicated 🙂

2. Kevin says:

GM:
How did you paste that TeX in the box?

\cfrac{Awesomeness}{Awesome}

1. GM says:

I spend many years wondering about that too – the dollar signs on their own do not work, you need to add “latex” immediately after the first one and then it works. Like this:

$\verb|$latex bla-bla$|$

1. Kevin says:

$\frac{\mathrm{Awesome}}{\mathrm{Thanks}}$

3. Heather Hastie says:

I disagree with the 50% response. Once she becomes part of the population that tests positive, the likelihood is 90%. At this point, imo, the data relating to those who tested negative becomes irrelevant for this particular woman. I am interested to know why I am wrong.

As a non-scientist I generally found the mathematics questions easier as you had information to work out the answers, but I couldn’t remember which gas was most prevalent in our atmosphere. Evolution is taught from an early age in New Zealand schools, and it’s a theory so I have no problem understanding. However, general recitation of facts I never learned is more difficult. Of course, you pick stuff up over the years and I actually do well on basic scientific knowledge tests, but that always surprises me given my level of education in the area.

1. Scott_In_OH says:

I think you slightly misread the question. The 10 women you identify as having tested positive are really the 10 women who actually do have cancer. In the question, 9 women without cancer test positive and 9 without test positive. Thus, someone with a positive reading has a 50% chance of actually having the disease.

2. “Once she becomes part of the population that tests positive, the likelihood is 90%.”

No. She could also be one of the 9 people that test positive but are in fact false positives.

Imagine all 100 people in a line. All of those with a positive response are told to step forward; that will be 18 people. We know that 9 of those represent false positives, so if you are in that group, you know that your chance of actually having cancer is 50%.

1. Heather Hastie says:

I get your reasoning, but neither of you has convinced me yet. The way I look at it, 10% of the women test positive. Of those 10%, 90% of them will actually have cancer. The fact that some of those who tested negative also have cancer is irrelevant to this particular woman. I know there must be something I’m not getting here. Perhaps I’m seeing an ambiguity that isn’t there.

1. No, let’s take this step by step. Of the 100, how many people had a positive test? If you say anything other than 18, then you are incorrect. That would be 18% positive responses, not 10%.

Next step, we know from the question that of the 10 women who do have cancer, 9 tested positive. So that’s 9% of the 100 that have a positive response that ACTUALLY have cancer.

9/18 = 50%

1. Perhaps some of the confusion is that there is 1 person who has cancer, but did not have a positive response; are you somehow including that person in your analysis? Because that person would be irrelevant, as the question is specifically asking about positive responses.

2. Heather Hastie says:

3. No problem. I experienced similar frustration with the famous Monty Hall problem. It took me at least half a dozen readings of the solution for me to finally fully understand it. Usually I have no issues with numerical problems, but that one just wasn’t clicking.

4. reasonshark says:

“Monty Hall problem”

Ha, me too. I got it when someone told me to try the same thing with 100 doors rather than 3, and suddenly it became obvious why the guy knowing what was behind the door mattered.

5. Dominic says:

I get that line of reasoning, but the question itself is poorly worded, because you can easily read it as just “what is the likelihood that she actually has a tumour” (treating the beginning part of the question as information meant to distract), making the answer 10%, as informed at the very start of the problem that 10 out of 100 women actually have tumours.

That said, I don’t know how you could make it clearer that you are supposed to include all the statistics, but the secondary part of the question strongly implies that you’re meant to ignore all the fluff.

3. Gregory Kusnick says:

You don’t need to remember which gas is most prevalent; all you need is basic knowledge of chemistry.

It can’t be oxygen because high concentrations of oxygen cause uncontrollable fire. (Remember Apollo 1?)

It can’t be hydrogen because hydrogen explodes violently. (Oh, the humanity!)

It can’t be carbon dioxide because too much of that kills people.

So all of those must exist at relatively low concentration in the atmosphere, leaving inert nitrogen as the only plausible choice for the majority component.

1. John Scanlon, FCD says:

Hydrogen only explodes violently (or rather, burns quite well) in the presence of lots of oxygen, so maybe we have a mainly H and N atmosphere with only traces of O?.

1. Gregory Kusnick says:

We know there’s non-negligible amounts of oxygen because we breathe it.

4. Ah, should’ve read this before I posted above! That’s what I get for being 2 days late to the game…

2. reasonshark says:

Yay! I got it right! And I used the technique you did, but I had the nagging feeling I was missing something. Apparently not. Woohoo! 😀

8. Hempenstein says:

According to the theory of evolution…

I don’t know why this jumped out at me now, but I think it might help a bit to draw a distinction between scientific and ordinary theories if we started referring to Evolutionary Theory instead.

After all, nobody refers to the Theory of Electromagnetism or the Theory of Gravity.

1. I agree with you in that it is a worthwhile endeavor, but I also doubt it would cause many creationists to change their minds, because they were never open to the concept in the first place, it’s just confirmation bias. When theists invoke the word theory to discredit scientific fact they are searching for a way to discredit a statement that doesn’t comport with their religious beliefs, not searching for the objective truth. They are seizing on the word theory in a desperate attempt to discredit the concept of evolution. If scientists and educators were to clarify the meaning of the word theory in this context to the theist cohort, they’d probably just find some other reason to refute scientific fact.

1. I don’t doubt your claim that theist’s are more motivated to cling to their beliefs than to accept reality is quite accurate as of 7.8.2014. And I can’t say with certainty whether consistent accurate employment of terms would perhaps accelerate increasing rates of acceptance of reality over fantastic explanations.

I expect, though, that the preponderance of misuse, sticking “theory” into sentences everywhere “hypothesis” belongs, weakens the import of Theory. And this misuse certainly does not hasten the day when a tipping point is reached, and empirical reasoning becomes the norm for the majority of humans instead of the present relatively rare exception.

It would be interesting to experiment with the practice of accurate usage and evaluate results. It isn’t as if it is just too undo-ably hard for the few who do not dispute the difference between hypothesis/speculation and Theory to quit saying theory-with-a-small-t when they discuss hypotheses or water cooler speculation.

Especially when compared to the difficulty factor in persuading the vastly more enormous number of people who resolutely cling to their favorite bullshit beliefs (because of Motivated Reasoning) to give themselves permission to let go of those and embrace reality instead. The real topic, here, is prioritizing critical thinking over any other method that claims ways of so-called “knowing”.

How do you lecture faith believers about their errors while visibly, blatantly, and consistently fucking up something this basic, yourself? All the while blaming your audience for its inability to distinguish that there is Theory, like Evolution, but at the same time there are also lots and lots of theories, too. Like multiple universes, or the odds of life on other planets.

And no, ID is not a Theory. It isn’t even a theory. Because it’s a failed hypothesis, that’s why. Well, you SHOULD already know what I mean. Figure it out for yourself already. And quit voting for school board candidates who demand biology classes teach the controversy and let the kids decide which theory they think is right. Dammit! There’s only one Theory. Except when you’re talking about multiverses and stuff like that. But you know what I mean.

2. John Scanlon, FCD says:

The wording of that adverbial phrase can, with a bit of imagination, be parsed in at least two ways:

[I believe that] According to the TOE…
According to the TOE [I believe that]…

I suspect that smart creationists, probably somewhat used to archaic syntax, would pick up on this ambiguity and may select ‘False’ to avoid assenting to the second version although they know the first is true.

9. Gordon Hill says:

In my experience the fear of there being no life after death if one becomes an unbeliever is a strong persuader to dismiss ToE, even among the unchurched Christians.

10. Sastra says:

If we want to eliminate creationism, we have to eliminate the kind of religious belief that makes people reject evolution. (That, of course, is not all religious belief: Unitarian Universalists, I suspect, have no problem with evolution.)

I think the root of the problem is deeper than just “the kind of religious belief.” I once gave a talk to the Unitarian Universalists on evolution (and the Dover decision) and during the discussion afterwards was surprised by how many UU’s waxed enthusiastically about how evolution proved God, or revealed God, or indicated God (or ‘Spirit’) to them. That’s because their understanding of evolution apparently included Teilhard de Chardin-style progression on the Great Chain of Spiritual Being. They were very surprised (and confused) when I tried to correct them.

But they were accepting evolution! They were supporting science! They belonged to the kind of people who were fine with evolution. This was a pro-evolution group. They were pro-science. Who cares if they use their understanding of science to support their personal Spirituality — or vice versa? Why does it matter?

From what I can tell the UU’s have no problem with evolution because UU’s don’t have a problem with evolution. It’s still tribal.

Imo the real problem behind acceptance of evolution is the idea that there are vast areas of truth which are only accessible to faith. There are basic facts about the ultimate nature of reality which are “learned” or “tested” the same way one would learn or treat a moral precept of way of life. You experience, you open, and you accept.

Once you work from this assumption, I think where you draw the line is going to be determined by which faith you have chosen to follow and/or which faith group you have chosen to join. The minute any scientific discovery or theory trips into some area, any area, which has arbitrarily been labeled “metaphysical” by someone then belief is now an option, as opposed to a rational conclusion. It’s all subjective. This is what I “choose” to believe. This is the person I want to be.

We don’t just see this happening with evolution: look at alternative medicine.

1. I am absolutely not surprised about your experience with a Unitarian group. Some years ago I had started attending meetings with a group of Unitarians, as I wanted to get involved in some community services. The subject of evolution often came up (once they learned that I taught it), their opinions were exactly like what you had described. Pro-evolution, and very much pro-God.

1. Kevin says:

My experience is that Unitarians believe in God in the way that an Atheist would believe in God, if an Atheist were to believe in God. Perplexing? That must be the life of a Unitarian upon introspection.

1. reasonshark says:

Pantheism?

1. John Scanlon, FCD says:

Well, it’s all or nothing, isn’t it?

2. reasonshark says:

This one seems surprisingly popular to religious compatibilists trying to buoy up god. Perhaps we should call this the Argument from Magnificence. Its bare bones premises seem to be:

1. If God exists, then he creates and thus gives rise to magnificent things.

2. This finding from science is magnificent.

3. If magnificent things exist, then God exists.

4. Magnificent things have been discovered by science (2).

5. Therefore God exists.

Note that 1 and 3 are inversions of each other, which is unfounded since it assumes that the relationship between God and magnificence is biconditional (i.e. they don’t realize or consider that one can exist without the other, and they assume that God and magnificence logically entail each other). That would possibly make it at least an implicit Commutation of Conditionals, a fallacy in logic, or another fallacy called Affirming the Consequent. It’s basically a failure to appreciate how inference and inductive logic work. For bonus points, add a sixth and seventh premise if the argument seems a little shaky:

6. God is magnificence itself.

7. Magnificence is God.

1. Sastra says:

Yes, it sucks … but in my experience UUs and other religious liberals absolutely hate formal arguments for (or against) the existence of God. Instead, they like to tell why they believe in God.

Yes, they’re making an underlying argument whenever they do this, but the assumption seems to be that as long as they’re not trying to convert you (the ultimate sin) their reasons — whatever they are — are perfectly legitimate. They can’t be assailed or attacked because hey, they’re just explaining why they believe … and so they do.

This attitude is usually accompanied with a confident belief in the special and sacred nature of personal faith.

11. Greg Esres says:

That rejection, to repeat, is not based on ignorance, for at all levels of OSI performance the religious know nearly as much about what evolution says as do the nonreligious. (This is borne out by previous work that asked even more about the theory of evolution.)

I’d guess that neither group really knows much about evolution, and neither group accepts evolution based on the evidence.

I would expect that the correlation between knowledge of evolution and belief in (oops, sorry, “acceptance of”) evolution would become greater once the knowledge passes a certain level.

1. moarscienceplz says:

Yes, I think you’re right. Most people have a kind of ‘bumper sticker’ knowledge of most of science. I once read a comment somewhere from a creationist who thought the geologic column was bogus because it was based on a tautology, “The rocks establish the age of the fossils, and the fossils establish the age of the rocks”. So he did know a bit about how geologists operate, but then he cherry-picks a couple of superficial sentences from whatever article he is reading and extrapolates it into a Bizzaro World view of geology that no normal geologist would even recognize.

1. Greg Esres says:

“The rocks establish the age of the fossils, and the fossils establish the age of the rocks”

Things like that are seductive even to nominally pro-science people. A friend of mine, very pro-science and smart, although not science-trained, fell for the 2nd Law of Thermodynamics argument against evolution, even though he accepted evolution. He just thought it was a good argument, but wasn’t sure why it was wrong.

1. moarscienceplz says:

Yes. I sometimes think people treat science like they treat sports. You become a fan of the pro-science or the anti-science team based on which side your father was on, and from then on you use half-remembered “facts” you got from your high school science classes, plus bumper-sticker quotes from the internet to show what a good fan you are for your chosen team.

12. I know of only one relevant study, Evolution and Religion: Attitudes of Scottish Bioscience Students to the Teaching of Evolutionary Biologyhttp://link.springer.com/article/10.1007%2Fs12052-012-0419-9. I discuss at http://wp.me/p21T1L-2O

Two relevant paragraphs: “All level 4 [now in their final year at uni] rejectors belonged to “low evolution” degree programs. It is clear that for most of them, no amount of scientific evidence would overcome their beliefs, a more entrenched position even than that taken by level 1 rejecters.” (“Low evolution” here describes courses such as psychology or pharmacology, as opposed to, say, zoology.)

So it would appear that logical and evidence based argument is futile with these folks.

This next bit was also very interesting.

“By level 4, our evolution rejection sample size was very small, but the importance of a belief precluding evolution remained the main factor. Our sample size for switching from rejection to acceptance was also small (n=7), but it is fascinating that these students were less affected by scientific evidence than by a realization that evolution and their religious beliefs were not in conflict.”

So for these students in Glasgow, reaching some kind of personal accommodation between the science and their faith was the path to accepting evolution.

“It is worth emphasizing that, although evolution rejection was strongly associated with holding a religious belief, the majority of believers accepted evolution.”

1. Oops, continuing: So if, as it seems, the coorelation between religiosity and evolution reection is stronger in the US than in the UK, one needs to ask why, and it may be that different tactics would succeed in different cultures.

1. I agree that one must consider the acculturation of the religious believers rather than simply the fact that they believe. However, we’ve been accommodating religious conservatives in the US for a while now and I’m woefully unimpressed with the results. Even with the establishment clause, the religious right-wing is far more politically powerful in America than in Western-Europe. These are voters who tend to read freedom of religion as “my religion gives me the freedom to tell others how to live.” See Florida Religious Freedom Restoration act of 1988, which is part of the state Florida Statutes (http://essexuu.org/flastat761.html#1) The Religious Freedom Restoration Act of 1993 (https://www.govtrack.us/congress/bills/103/hr1308/text) and the recent SCOTUS decision regarding the denial of health coverage on religious grounds. IMO the responsibility lies with the theists. They need to “accommodate” objective reality.

2. Diana MacPherson says:

But what evolution? God guided? That isn’t really right. That is like faux evolution. It is fevolution.

1. GBJames says:

“Fauxvolution” is the correct spelling, I think. 😉

1. Diana MacPherson says:

Yes, your portmanteau is better than mine!

13. eric says:

That rejection, to repeat, is not based on ignorance, for at all levels of OSI performance the religious know nearly as much about what evolution says as do the nonreligious. (This is borne out by previous work that asked even more about the theory of evolution.)

I would be very curious about that previous work, because I don’t think you can really make that conclusion from this study. The question was so simple and basic that I don’t think you can conclude much more than the very limited: “at all levels of OSI performance, the religious know that the TOE says humans evolved in about the same numbers as the nonreligious.”

Your “nearly as much” would imply to me a much stronger understanding than what this test assesses. It would, just for example, imply that the religious could describe the mechanism of natural selection with about as much accuracy as the nonreligious. But the constant occurrence of the ‘tornado in a junkyard’ trope amongst creationists tells me that they don’t understand the mechanism as well as nonfundamentalist laypeople.

As an analogy, consider this. You would never say that asking people “what does 5+6 equal?” is a good measure of whether they all understand math “about as well” as each other. The question is too simple to draw that conclusion. So too here; the question about evolution is too simple to draw the conclusion that the answerers understand the theory of evolution equally.

1. “So too here; the question about evolution is too simple to draw the conclusion that the answerers understand the theory of evolution equally.”

I think that this is a great point. If it’s not out there already, I’d like to see an “evolution literacy test”, designed to ferret out common misunderstandings and with plenty of fastballs in there to test people who (like myself) probably don’t know nearly enough about the subject as they think they do.

1. eric says:

The test-makers here had obviously thought about this problem when it came to numeracy; that’s why they have multiple math/logic questions of increasing difficulty. But they didn’t do the same for evolution, which is perplexing if they were studying evolution acceptance. If, OTOH, evolution acceptance was not the focus but rather just an interesting and unexpected result of a study intended to look at some other effect, then I can understand why they might not have included a range of easy-to-hard questions on evolution.

2. Horrabin says:

I agree. Someone who knows the correct answer (according to the theory of evolution, human beings developed from earlier forms of animals) could also believe all kinds of incorrect things about what the theory says–otherwise we wouldn’t be faced with creationists saying things about cats turning into dogs, “why are there still monkeys”, or saying that evolution is the theory of random chance.

The point about religious belief being the main obstacle to acceptance of evolution is still valid, of course, I just don’t think that this proves that the religious understand the theory in any meaningful way.

1. Jesper Both Pedersen says:

I’m not so sure about this. Actual disinformation/misconceptions may account for a small percentage, but how to decide what constitutes an adequate understanding of evolution in that respect?

Non-religious people at a comparable educational level may have several misconceptions as well, but that doesn’t exclude them for accepting the truth of it.

I bet we’ll see the same level of resistance against chemistry when/if the exact mechanism that started life on this planet is discovered.

And it will be interersting to see how religious people will react when/if we find life elsewhere in this universe and it evolves just like we do.

The reasons for not accepting evolution as fact are entirely emotional, imo.

1. eric says:

“how to decide what constitutes an adequate understanding of evolution in that respect?”

Well, for starters, the test-makers could’ve done for evolution exactly what they did for numeracy. Which was to make up several different questions of different difficulty and ask them all. Then you check whether there’s a correlation between non-belief and not getting the harder questions right. No correllation would be much better evidence (than the current test) that Jerry is right. OTOH if you see fewer people disbelieving who get the harder questions right, then its fair to say that understanding may have something to do with acceptance (or vice versa).

1. Jesper Both Pedersen says:

Well, I guess that pretty much depends on what previous questions they asked about evolution.

But I think the following is very telling:

When the clause, “[a]ccording to the theory of evolution . . .” introduces the proposition “human beings, as we know them today, developed from earlier species of animals” (NSF 2006, 2014), the discrepancy between relatively religious and relatively non-religious test-takers disappears!

In other words they know what the theory states, but they refuse to acknowledge it as fact.

Religion isn’t the only problem, but lack of personal acceptance of evolution after having received a minimal amount of education on the subject it is entirely, again imo, an emotional resistance that remains.

I don’t know much about evolution, but I know enough about other animals to realize I am one, if you catch my drift.

How evolution is taught in religious communities is of course also of vital importance.

1. Jesper Both Pedersen says:

That second paragraph got messed up. 🙂

Here it is with corrections:

Religion isn’t the only problem, but lack of personal acceptance of evolution after having received a minimal amount of education on the subject is entirely, again imo, emotional.

1. Heather Hastie says:

Rejection of Evolutionary Theory is largely emotional, but I think it must be harder to reject if you have a proper understanding of it. If, for example, you don’t get the natural selection part, which many YECs don’t seem to, it’s probably easier to reject as it wouldn’t make as much sense. They also frequently don’t seem to get how gradual the change is. They seem to expect all change to be big and outwardly obvious, like a monkey giving birth to a human, which, of course, would actually disprove evolution.

I agree some more difficult questions on evolution would have given better results about whether participants really understood evolution. Knowing it means we evolved from other animals is no big deal and doesn’t prove an understanding of the theory.

2. Jesper Both Pedersen says:

Rejection of Evolutionary Theory is largely emotional, but I think it must be harder to reject if you have a proper understanding of it. If, for example, you don’t get the natural selection part, which many YECs don’t seem to, it’s probably easier to reject as it wouldn’t make as much sense. They also frequently don’t seem to get how gradual the change is. They seem to expect all change to be big and outwardly obvious, like a monkey giving birth to a human, which, of course, would actually disprove evolution.

Some of it is no doubt plain ignorance, but I also can’t help wondering how much of it is talking points.

There are no scientific refutations to evolution so unless you’re prepared to do a ton of dishonest intellectual legwork and devise a personal alternate hypothesis yourself, the easy and often only way to oppose evolution is through shallow objections devised by other people.

In other words, I think many of these objections have evolved into memes that are being repetitively regurgitated simply beacuse there are no better objections from a religious viewpoint.

I agree some more difficult questions on evolution would have given better results about whether participants really understood evolution. Knowing it means we evolved from other animals is no big deal and doesn’t prove an understanding of the theory.

According to Jerry’s post they did ask more questions about evolution before this test, but of course we don’t know how good they were.

But to many people it is a very big deal to know that we evolved from other animals. It is to me too.

3. Jesper Both Pedersen says:

I’m sorry, but I suck at wordpress, so here goes again with old-fashioned quotation signs:

“Rejection of Evolutionary Theory is largely emotional, but I think it must be harder to reject if you have a proper understanding of it. If, for example, you don’t get the natural selection part, which many YECs don’t seem to, it’s probably easier to reject as it wouldn’t make as much sense. They also frequently don’t seem to get how gradual the change is. They seem to expect all change to be big and outwardly obvious, like a monkey giving birth to a human, which, of course, would actually disprove evolution.”

Some of it is no doubt plain ignorance, but I also can’t help wondering how much of it is talking points.

There are no scientific refutations to evolution so unless you’re prepared to do a ton of dishonest intellectual legwork and devise a personal alternate hypothesis yourself, the easy and often only way to oppose evolution is through shallow objections devised by other people.

In other words, I think many of these objections have evolved into memes that are being repetitively regurgitated simply beacuse there are no better objections from a religious viewpoint.

“I agree some more difficult questions on evolution would have given better results about whether participants really understood evolution. Knowing it means we evolved from other animals is no big deal and doesn’t prove an understanding of the theory.”

According to Jerry’s post they did ask more questions about evolution before this test, but of course we don’t know how good they were.

But to many people it is a very big deal to know that we evolved from other animals. It is to me too.

I hope that was better. 🙂

2. eric says:

The single question tells you they understand that evolution says humans evolved. It does not tell you why they are rejecting it. If, for example, they reject it because they think the TOE says humans evolved when a chimp gave birth to a human, and they find that unlikely, then I think it would be fair to say that they are rejecting it due to misunderstanding it. Don’t you agree? After all, *I* would object to a theory that said that, and I’m not committed to any religion.

That is why, if you want to figure out whether the rejection comes from misunderstanding vs. religious commitment, you have to explore just what it is they understand about evolution. That the TOE says humans evolved is a good starting point, but it is not enough to determine whether someone may be rejecting the TOE because they misunderstand how humans evolved.

1. Jesper Both Pedersen says:

“The single question tells you they understand that evolution says humans evolved. It does not tell you why they are rejecting it. If, for example, they reject it because they think the TOE says humans evolved when a chimp gave birth to a human, and they find that unlikely, then I think it would be fair to say that they are rejecting it due to misunderstanding it. Don’t you agree? After all, *I* would object to a theory that said that, and I’m not committed to any religion.”

I agree that such misconceptions could account for a small percentage, but I’m also inclined to think that many of these people know that the theory doesn’t state we evolved from chimps. If that was a common misconception then why doesn’t it repeat itself in non-religious answers as well?

My contention is that this solely is an emotional rejection, in these particular case encouraged by religion, and that the ability to look at yourself as an animal just like other animals is not rooted in educational level. Many are fine and dandy with other animals having evolved, but when it comes to humans…..well, we’re unique and that uniqueness is not easily compromised if you grow up thinking this was a gift given to you by god. If evolution is true, then we’re not really special after all.

That’s a hurdle to overcome regardless of knowledge and education.

“That is why, if you want to figure out whether the rejection comes from misunderstanding vs. religious commitment, you have to explore just what it is they understand about evolution. That the TOE says humans evolved is a good starting point, but it is not enough to determine whether someone may be rejecting the TOE because they misunderstand how humans evolved.”

There is no misunderstanding, imo. They display ( according to the authors ) more than adequate knowledge regarding animals evolving from other animals. The only thing missing from the equation is us.

That’s why I contend that rejection of evolution given an absolute minimal amount of education on the subject is entirely emotional. The concept is so simple to understand, organisms evolve from other organisms, that you don’t need elaboration on how they do it to understand or accept it.

That’s why I raised the question about what constitutes “adequate” knowledge of evolution and subsequently how to objectively decide what is lack of knowledge and what is faith.

If there were a legitimate alternative to ToE, then yes, but there isn’t.

The reason these religious objections sounds so dumb and downright ignorant is simply that there are none better.

This really is the best religion can do when matched up against evolution, imo.

2. Kirth Gersen says:

Exactly this. Imagine the following questions:

T/F Evolution is largely driven by random chance.
T/F Evolution has never been observed.
T/F Although transitional forms are assumed by the theory, no “missing links” have ever been found in the actual fossil record.

Check the % correct/incorrect on those vs. the other data. I suspect we’ll find that (a) religious people get them wrong a lot more often, and (b) people who get them wrong correlate very strongly with people who do not accept evolution.

14. sponge bob says:

Climate change/global warming denial is definitely rooted in religion sometimes. I know this from personal experience.

Just like evolution, it’s hard to convince the group about man-made global warming, because both imply god isn’t in control or doesn’t exist or both.

1. I am looking forward to learning about the bases for rejection of global warming. My opinion, which is mine, is that rejection has diverse reasons. Some reject it b/c they believe God Wouldn’t Allow It. But I think that a lot of people reject it b/c the energy industry has mounted an effective campaign to sow doubt, and many people have been fooled by that. In any case, we will see.

2. eric says:

But its still inconsistent. These same people who think global warming is a hit to God’s dominion don’t seem to think that lightning rods attracting lightning is a hit to God’s dominion, or that dykes or levees anger God. Humans have clearly altered our environment, and there are many cases where us claiming to have altered it is taken without a batted eye and not considered blasphemous. So why is the thought blasphemous this time?

1. Kirth Gersen says:

My understanding is that there was a huge backlash against the lightning rod when Franklin introducted it. It was only after years of undeniably successful use, coupled with lack of divine retribution for its use, that people started to realize, “Hey, these things do work, and are not a challenge to our religion.”

1. eric says:

Yes, I used that example intentionally. The point is, today’s fundies seem to have a double standard – a very obvious one, if you know your history. How do they justify that double standard?

1. John Scanlon, FCD says:

How do nationalists, sports fans, and any other variety of chauvinist justify a double standard?

“it’s ME vs THEM. What do you think?”

15. SA Gould says:

They need a lower-level questionnaire. I doubt that the average person understands how water can erode rocks, plants create oxygen or animals can make and use tools.

And do the truly religious believe/know they are living with tiny creatures that eat their dead skin? (What kind of a loving god would allow that?)

1. Kevin says:

Or that radioisotope dating comes from physics, which, by itself as a subject, does not care whether evolution is true or not. Physics permits evolution, but it does not necessarily make evolution the case. Physics does tell us clearly that parts of the world are several billion years old and everyone should know that.

As for little creatures eating dead skin. What about the poor sod who escaped with his life after being bitten by a great white. He appears to have manufactured the inconceivable belief that God saved him from the shark??? Pathetic.

16. darrelle says:

I agree that people are less accepting of evolution compared to other sciences due largely to their commitment to their religious beliefs. This study certainly seems to clearly show that. But I am not so sure that the average persons understanding of science is relevant at all.

It seems to me that the average person’s acceptance, or not, of any science has more to do with argument from authority and whatever the community zeitgeist is than their understanding of the science. The questions on the OSI don’t seem to probe for understanding of why science has reached the conclusions it has, but only what those conclusions are.

For example, the one evolution question that asks if the TOE says that humans evolved from earlier animals. I think it is a fairly small percentage of the general population that have a decent understanding of why or how the TOE leads to that conclusion. And I think the same holds for any branch of science.

It just comes down to a contest between authorities. And the large difference seen in this study is due to the fact that many of the findings of the TOE, particularly in the context of human beings, are perceived as being directly at odds with the highest authority the majority of the population (US anyway) claim.

17. “81% of Americans at least know what the theory says. That’s still pretty low to me; how can one not know what biological evolution is?”

I think 81% is very encouraging, given the number of adults who get through high school without a science class that teaches evolution (or drop out before taking one), or whose literacy level and reading comprehension remain low even if they do graduate.

1. GM says:

It is hard to believe indeed, but if you go out and talk with “regular” people, you will find out that they don’t care about these things to such an extent that this is not at all that surprising, especially for older people. The people reading this blog are a very self-selected population.

Remember that the way many teachers deal with having to teach evolution to a deeply religious audience is by basically skipping it. And in the same time there is a huge number of people who go through school without having learned anything; there are tons of people who struggle with basic reading, writing and math, many who drop out, etc., and it’s not like they are getting educated through other sources. It is completely possible.

18. couchloc says:

“those who reject evolution do so largely on religious grounds, not because they don’t know what evolution is. In other words, Kahan concludes that American rejection of evolution is not due to lack of information or ignorance”

I think this shows there is a problem with what many around here think is the right way to combat religious believers (I’m a philosopher). The above research suggests that many religious believers know what evolution is, but this knowledge doesn’t undermine their committments to their religious beliefs. This says to me that focusing on teaching evolution as a means to combat religious believers is the wrong approach. This is not that surprising in the end, since we know there’s no logical incompatibility between evolution and the existence of God, and that learning about evolution does not require one give up one’s religious beliefs if one wants. As a result I think that the efforts by Dawkins and others who focus on teaching the public about evolution is not really the best approach in the debate about atheism. As an alternative might I suggest that it would be better to focus on philosophical and social problems with religion that the average person more directly relates to. I’m talking about teaching the problem of evil (Hume), religion as oppression (Marx), religion as subservience (Nietzsche), religion as sexist (Freud). Students respond to these views in their philosophy classes more readily than the worries about the theory of evolution in my view. Notice also that countries like France (who are 73% atheist) require a year of philosophy in high school. This is no accident.

1. Sastra says:

I agree — but question your using Richard Dawkins as an example of a scientist who thinks that the answer to evolution denial and theism is to “focus on teaching the public about evolution.” I think he goes much further in that he gets into why evolutionary theory acts as what philosopher Dennett calls a “universal acid,” thus getting into a philosophical problem to which I think people can indeed relate — judging by the anger it engenders.

Although the ethical arguments against the existence of god are often effective, I think that too much focus on the crimes of organized traditional religion only leads to a heartfelt and enthusiastic embrace of disorganized personal religion — withthe accompanying smug assumption that atheists just never realized that God is a vitalistic energy of Love or similar claptrap.

1. Jesper Both Pedersen says:

Although the ethical arguments against the existence of god are often effective, I think that too much focus on the crimes of organized traditional religion only leads to a heartfelt and enthusiastic embrace of disorganized personal religion — withthe accompanying smug assumption that atheists just never realized that God is a vitalistic energy of Love or similar claptrap.

There’s also the danger of judging the present by the past which instinctively feels unfair to the accused party regardless of validity in the criticism.

It’s the same feeling we get when we’re accused of being Stalinists because of our godlessness.

2. eric says:

I think that the efforts by Dawkins and others who focus on teaching the public about evolution is not really the best approach in the debate about atheism.

Dawkins is free to promote atheism if that’s what he wants to do. However, I think you misconstrue his goals if you think he’s teaching the public about evolution primarily to support atheism. I think he teaches the public about evolution primarily to support evolution education. I think if someone read a book like Selfish Gene and told Sir Richard that it convinced them that life on earth evolved through descent with modification (etc…), but that they still believed in God, he’d be pretty happy with that result.

1. GBJames says:

I think he would conclude that the reader hadn’t understood The Selfish Gene. Or at least that the reader hadn’t understood the implications of the book.

2. couchloc says:

I didn’t mean to suggest that he teaches evolution primarily to support atheism. He is of course right to teach the public about evolution in general. I’m trying to say that when it comes to arguing against religious believers and changing their minds the focus on evolutionary theory is the wrong focus I think. In my view we would do better to focus on the arguments of Hume, Marx, Freud, etc. and the reason is that these arguments pose more directly engaging problems for believers. Freud’s question “Is Christianity sexist?” raises immediate, accessible problems for the average person to reflect on. Where the question “Is Christianity inconsistent with evolution?” is more abstract and difficult to motivate without lots of background. Which one do you think the average women would be concerned with?

1. eric says:

Depends on the person, I guess. If you’ve got a believer who puts a lot of stock on the historical veracity of Genesis-Exodus, then evolution-style arguments are going to be more relevant than theodicy-style ones. Particularly for divine command theory type believers: I doubt someone who thinks it was okay for God to order the rape and murder of the Israelites’ enemies is going to be bothered by something as minor as a little God-ordered sexism.

OTOH if you’ve got a believer who is already nonliteral in terms of how they read Genesis-Exodus, then yes, I can see the theodicy-type arguments being a lot more relevant and effective.

3. “This is not that surprising in the end, since we know there’s no logical incompatibility between evolution and the existence of God, and that learning about evolution does not require one give up one’s religious beliefs if one wants.”

Depends on the God. If we are talking about the 3-O God, who knows everything past, present, and future, then there does seem to be an incompatiblity. This is because at some level, mutations are subject to quantam indeterminacy and thus the path of evolution cannot be known with 100% accuracy.

There is also a “weaker” form of logical incompatibility, as evolution is so utterly wasteful and results in so much suffering in the natural world. For instance, one of the most basic engines of evolutionary change is the fact that far more offspring are produced that can possible survive. This does not seem consistent with a loving, competent creator who could have used a much more rational and efficient mechanism such as special creation to achieve His creative ends. I say that this incompatibility is “weaker”, because apparently Sophisticated Theologians have devised ways where this wasteful and cruel aspect of evolution by natural selection would in fact be compatible with a perfect, loving creator.

1. couchloc says:

Yes there are certain ways to describe some of the views as being logically incompatible if one wants. But if you have to go through quantum indeterminacy you’re going to have a hard time with the average person I think. My point is that appeals to the complexities of evolutionary theory and things like quantum indeterminncy don’t reach the average person as easily as the philosophical concerns raised by Hume/Marx/Freud. That is why I think they are a better focus.

4. John Scanlon, FCD says:

“focusing on teaching evolution as a means to combat religious believers is the wrong approach”

How about focusing on teaching evolution as a means to combat ignorance about evolution in believers and unbelievers alike? Would that be alright?
(Who refuses to teach about the physics, geology and biology involved in evidence for evolution? – oh, only the religious nutjobs? How would they feel about putting more Hume, Marx, Nietzsche and Freud into the syllabus, I wonder.)

19. Jim Thomerson says:

If evolution rejectors have good knowledge of the phenomenon, how come every comment about evolution I see from creationists and other antievolutionists strikes me as reflecting either ignorance (to be charitable) or dishonesty (as supported by the study)

20. Kevin says:

“Climate Science Communication and the Measurement Problem” is a good article. If anything, it illustrates that there are quantifiable correlations between people’s beliefs and education.

A better study would look at simple logic and simple constraints on physical or mathematical concepts that few if any would doubt.

For example consider the following survey questions:

Does gravity exist?

Does gravity make objects go back to earth?

If a soccer player legally kicks a ball into a goal does that team get a point?

If you swim only one lap of a pool, how many laps have you swum?

Is there a God?

Does life begin at conception?

Is climate change anthropogenic?

These kinds of questions, when answered together, illustrate that beliefs do not change reality. Existence is what it is. Beliefs will vary, and knowledge may or may not change beliefs. What is confusing is that knowledge can change existence. Using science, one can predict and even enforce regularities in nature. Even more confusing is that it does not require sentience. A cat can establish patterns and understand where prey might be found on a regular basis. That changes reality. But the hope that a little rabbit can be found down specific hole is not going to make a difference to a cat.

21. Excellent piece. A potential problem may appear with the follow-up piece, summarized by Pascal Boyer in “Religion Explained,” page 135:

1. The mind it takes to have religion is the standard architecture that we all have by virtue of being members of the species. (We need no special mentality or mind.)

2. Because of decoupling and specialization, human minds are sensitive to a particular range of cultural gadgets.

3. (To anticipate): Religious concepts too are probably successful to the extent that they activate inference systems.

In short: it’s not merely education, it’s the way we’re built, for which we can blame the tinkering of natural selection. Ignore that, expect that education alone can succeed, and attempts to eradicate religion will fail.

22. reasonshark says:

A contributing factor seems to me to be that religious beliefs and practices reach people early on in their lives, combined with the fact that they are encouraged throughout to commit to these beliefs and practices emotionally. When a contrary idea like evolution is discovered later on, and when their religious views are cast into doubt, what should be a matter of dispassionate inquiry upsets deeply ingrained states of mind, and it’s interpreted as an emotional threat.

It’s significant because this early and heavy-handed teaching produces two things antithetical to rational inquiry. One is an instinctive but largely unchallenged blurring of personal identity, emotional liking, and long-held belief (especially if it’s culturally traditional), such that other views are not only unfamiliar, alien, and lacking in emotional appeal, but that one believing in another view comes across as fundamentally inconceivable, like rewriting one’s character from scratch. The other is being taught that their beliefs have strong consequences on their behaviour, and so challenging those beliefs will have dire consequences. One example would be believing that evolution implies atheism, or that it causes people to become immoral and nihilistic.

This suggests some ways of weakening the religiosity of some parts of the population:

1. Actively teach children from early ages onwards about, and encourage citizens to explore, other religions or even cultures besides the ones they grew up with. Better still, get them regularly in contact with them. A degree of cosmopolitanism would at least water down the cultural parochialism.

2. Encourage dispassionate inquiry and raise awareness of intuition’s flaws and biases that distort one’s judgement, with rigorous application to oneself (as it’s too easy to pick someone else’s errors and ignore your own).

3. Question seriously how we know what we know (i.e. skepticism and rationalism). A lesson in epistemology can’t hurt.

4. Make the distinction clear between ideas and individuals, i.e. that an attack on the former is not an attack on the latter.

Acceptance of evolution will probably increase over the next decade or so, but perhaps it can be accelerated if those cultural elements that inhibit it (parochialism, emotionalism, lack of rational skepticism and thus lack of self-improvement drives, anti-intellectual romanticism, etc.) are defused as well. And the whole thing has to have the clean tone of improvement, if only to stop detractors from distracting fence-sitters with propagandist complaints about “angry atheists”.

1. reasonshark says:

Well OK, evolution does imply atheism, and my last sentence is a bit opaque. What I meant was that it can’t hurt to conduct the above in a non-confrontational but affirmative and assertive tone, not because we’re wrong if we don’t act like saints, but because it makes it harder for the other side to use character stereotypes and genetic fallacies to dismiss our points. Like how civil disobedience and pacificism make it more obvious that the establishment is not practising self-defence but are just oppressors, because attacking a non-violent group doesn’t look right.

23. Pat Shields says:

It seems a bit odd and concerning that only 60% of people were able to answer the the Earth orbits the Sun.