Can scientific theories be falsified? One scientist says no

September 8, 2020 • 10:15 am

The provocative title of the Scientific American Article below, by physicist Mano Singham, is, I think, deeply misleading.  The idea that science progresses by eliminating incorrect explanations, which is what falsification is all about, seems to me not only a good strategy, but one that’s historically worked very well. To say it’s a myth is not even wrong.

But let’s hear why Singham says that falsification can’t work. Click on the screenshot to read his piece.


Before we get to Singham’s argument, we notice that we can immediately think of scientific theories that have been definitively falsified. One is that the Earth is flat. That has been falsified by any number of observations, and now nobody except loons accepts a flat planet. Alternatively, the Genesis story of creation, once a “scientific” explanation for the origin of life and, especially, humans, has also been falsified, also by any number of observations.  It was replaced by a better theory: evolution, and you can see the process of falsification by reading The Origin, as everyone should.  Darwin not only adduces evidence for evolution from biogeography, embryology, the fossil record, vestigial organs, and so on, but at the same time notes how these observations do not comport with creationism, the main competing hypothesis at the time. The falsification of creationism is why Darwin was so worried that religious people would reject his theory.

For if observations comport with both of two competing theories, this gives us no way to determine which is the better one. Darwin shows in his biogeography chapters, for example, how the distribution of animals and plants on Earth jibes with an evolutionary theory combined with the idea that organisms disperse, but cannot be explained by creationism. (Why would the creator not put native mammals, freshwater fish, and amphibians on oceanic islands?) The book’s falsification of creationism combined with its support of evolution meant that, within about a decade after 1859, nearly all educated people accepted that Biblical creationism had been falsified.

Why, then, given the above, does Singham think that falsification—the classic strategy of scientific advance limned by Karl Popper—is a “myth”?  He gives two reasons (he’s referring to Haldane’s “Precambrian rabbit” as a proposed falsification of evolution):

1.) Falsification is complicated. Singham says this:

But the field known as science studies (comprising the history, philosophy and sociology of science) has shown that falsification cannot work even in principle. This is because an experimental result is not a simple fact obtained directly from nature. Identifying and dating Haldane’s bone involves using many other theories from diverse fields, including physics, chemistry and geology. Similarly, a theoretical prediction is never the product of a single theory but also requires using many other theories. When a “theoretical” prediction disagrees with “experimental” data, what this tells us is that that there is a disagreement between two sets of theories, so we cannot say that any particular theory is falsified.

Fortunately, falsification—or any other philosophy of science—is not necessary for the actual practice of science.

I don’t quite get this. If many lines of evidence (or many scientific fields) converge on a conclusion that contradicts an existing theory (evolution in this case), that doesn’t mean that falsification doesn’t work, just that sometimes it’s not so easy. In fact, in the case of a Precambrian rabbit, scientists wouldn’t take a single observation as overturning a theory supported by so much evidence in favor of a theory—creationism—supported by none. Scientists would work hard to make sure that date wasn’t an anomaly, whether the rabbit somehow got itself insinuated in Precambrian sediments, and so on. Further, we’d like more than one fossil, for a theory as well established as evolution would require a multiplicity of “wrongly placed” fossils to make us question it. This doesn’t mean that falsification is a myth, just that when you use it against a theory that’s very well supported, you have to use it many times.

And sometimes an experimental result is indeed a “simple fact” obtained directly from nature. The idea of a pancake Earth is simply refuted by sending a satellite around the planet and not finding an edge. This case also shows that Singham’s claim that “a theoretical prediction is never the product of any single theory” is wrong as well. A flat earth (some get the idea from the Bible) is a single theory, not depending on “many other theories.”

Another example is Meselson and Stahl‘s lovely and definitive refutation of two models of DNA replication (“conservative” and “dispersive”), confirming the “semiconservative” model with a simple and beautiful experiment involving centrifugation of radioactively labeled DNA as it replicated.  Just because radiochemistry, centrifugation, and biochemistry were involved doesn’t make the experiment any less of a falsification. And there were only two other credible theories being tested, not “many other theories.” Since then, the entire science of molecular genetics has depended on their 1958 result, and it’s held up. If this isn’t an instance of verification of a true theory by falsifying alternatives, I don’t know what is.

Here’s Singham’s second reason why falsification is a “myth”:

2.) Pseudoscientists, cranks, and enthusiasts claim that they have data falsifying “consensus” theories, and this tactic makes falsification a dubious strategy. Again, I don’t quite get this, but here’s what Singham says:

A knowledge of the historic and philosophical background gives that kind of independence from prejudices of his [Einstein’s] generation from which most scientists are suffering. . .

. . . this knowledge equips people to better argue against antiscience forces that use the same strategy over and over again, whether it is about the dangers of tobacco, climate change, vaccinations or evolution. Their goal is to exploit the slivers of doubt and discrepant results that always exist in science in order to challenge the consensus views of scientific experts. They fund and report their own results that go counter to the scientific consensus in this or that narrow area and then argue that they have falsified the consensus. In their book Merchants of Doubt, historians Naomi Oreskes and Erik M. Conway say that for these groups “[t]he goal was to fight science with science—or at least with the gaps and uncertainties in existing science, and with scientific research that could be used to deflect attention from the main event.”

But this no more refutes the value of falsification than it refutes the value of science itself. For the same zealots and pseudoscientists who use the idea of falsification also pretend to use the methods of science. I don’t think I need say more about this.

Finally, near the end of his article Singham comes close to admitting that yes, falsification works:

Science studies provide supporters of science with better arguments to combat these critics, by showing that the strength of scientific conclusions arises because credible experts use comprehensive bodies of evidence to arrive at consensus judgments about whether a theory should be retained or rejected in favor of a new one. These consensus judgments are what have enabled the astounding levels of success that have revolutionized our lives for the better.

But how do you go about rejecting a consensus theory, like creationism, in favor of a new one? You have to find evidence that comports with the new one and not with the consensus. And that is falsification.

Now it’s possible that there is no competing theory, and you’re just looking for evidence that comports with the only theory you have. But even that is, in some sense, falsification: falsification of the idea that your theory is wrong, even if you don’t have an alternative. If you think benzene has six carbon atoms, then your alternative theory is that benzene doesn’t have six carbon atoms, but more or fewer, and you look for evidence for falsifying one or the other of these theories.

I think Singham intended to support the value of science studies—the history and philosophy of science—at a time when some people denigrate them. Richard Feynman famously said “philosophy of science is as useful to scientists as ornithology is to birds”.  I don’t agree with him on either count—ornithology is useful to birds, by helping conserve them, and philosophy of science can help us think more clearly about our problems and methods. But sometimes science studies can be impediments by confusing people about the nature of science or making insupportable or useless statements, like there’s no external reality independent of our senses. And one of these impediments is the claim that falsification is a myth.

h/t: Barry

An innocent joke about worms triggers a scientific firestorm on Twitter

August 3, 2020 • 9:00 am

I’d heard about this kerfuffle, and wrote it off as a tempest in a petri dish until I saw this article in the Daily Beast. Surprisingly, the Beast, which I thought was on the liberal side of the spectrum,  took sides against the Perpetually Offended, as it should have given the ridiculous nature of the fracas.

You can read about it at the website below or just peruse my short take her (click on screenshot):

The ignition: Michael Eisen, a well known professor of genetics at UC Berkeley, an advocate for “open” science publishing, and editor of the respected journal e-Life, answered a Twitter question about the most overhyped animal.  He was clearly joking, as you can see below (Eisen’s also known for his sense of humor). Eisen suggested Caenorhabditis elegans, a roundworm that has been immensely useful in unraveling the genetics of development. It’s a “model organism,” which means that it’s studied in the lab rather than the wild.

This kind of mock dissing is applied to other “model organisms”, like the Drosophila I work on. That species, too, has taught us an immense amount about genetics and development, but throughout my career I’ve had to endure jokes about it not being a “real” species. I always laughed these off because a). it is a real species found in nature (it’s now a human commensal) and b). starting with T. H. Morgan in the early 1900s, it’s been the insect species used to study classical genetics, molecular genetics, and now evolutionary developmental biology (“evo devo”). From that species we’ve learned, for instance, about sex chromosomes, about gene duplication, about the linkage of genes on chromosomes, and so on—and that’s just the classical-genetics stuff.

I don’t think Eisen knew what he was getting into with his humorous response. (The worm is also a self-fertilizing hermaphrodite, which is what he means by “occasionally they fuck themselves”.)

The pushback began immediately, as if Eisen somehow didn’t realize the importance of the worm. He quickly made it clear that he was joking:

But he had to clarify himself again, for one clarification only leads to another if you’re facing the Woke.  Although scientists have previously not been that immersed in Wokeness, they’re starting to become that way big time, buffeted by the winds of social change and perhaps a bit peevish and restive from the pandemic.

Eisen even got faulted for using the word “fuck,” for his “frat boy humor” and for having a bit of fun on the Internet:

Some people, like Coleen Murphy, took umbrage because they had “grants and paper rejected based on *exactly* this reason.” I seriously doubt that this is literally true. Perhaps the rejections were based on a perceived lack of generality from results in C. elegans to other metazoan species, but they could have been rejected for other reasons. At any rate, that’s no reason to dump on Eisen. What we see here is animus aimed at editors and reviewers directed instead at Eisen:

It wasn’t long before the specter of racism insinuated itself into the discussion. But even black scientists pushed back:

The Beast gives a bit more information. (Ahna Skop’s tweets are now hidden.) The invocation of marginalized people is the new version of an old rule—I can’t remember its name—which said something like “Any Internet argument will eventually devolve to comparisons with Hitler.” Now it’s “systemic racism” instead of Hitler.

By far the most prolific poster in this vein was Ahna Skop, associate professor of genetics at the University of Wisconsin-Madison and previous recipient of a Diversity, Equality and Inclusion-based award in 2018. Dr. Skop—who did not respond to a request for comment by The Daily Beast—argued extensively that making jokes about worms was merely the tip of the iceberg when it came to making jokes about marginalized identities, or an example of a ‘bystander effect’, a psychological theory arguing that individuals are less likely to offer help to a victim in a crowd. (For is it not said: First they came for the worm people, and I said nothing, as I was not a worm person?)

In the resulting threads, Dr. Skop—who identifies as “part Eastern Band Cherokee” and “disabled with EDS”—and others consistently failed to publicly respond to Black scientists like herpetologist Chelsea Connor, who tried to point out that this was a ridiculous conflation.  In a private communication Connor shared with The Daily Beast, Skop doubled down, arguing that as she had previously been harmed by entrenched sexism, her concerns regarding the worm joke were justified.

Oy!  But sensible people like Dr. Berg tried to defuse the crisis with the correct claim “it was only a joke”. She included screenshots of Skop’s tweets:

Let us bring this ludicrous squabble to an end with a quote from the Beast (criticizing the Offended) and a cartoon encapsulating the gist of the battle:

In falsely equating the real oppression of people belonging to marginalized groups to a Twitter joke about a roundworm, Wormageddon 2020 offers a clear example of how white and white-passing women misuse the language of diversity, equality and inclusion, with little accountability and self-awareness, and without any interest in the hurt that such frivolous invocations cause the people they’re theoretically defending. Someone who took the struggles that marginalized people face in academia seriously, after all, would not invoke them to win a Twitter argument about whether a worm joke is rude. “That comparison should never have been the knee-jerk reaction for them,” Connor said. “And then the response [to criticism] should have been better… The harm done stays with us and they get to log out and forget that this ever happened and let it ‘blow over’ meanwhile we have to work to fix what they did.”

My take: Eisen and Connor 42, Offended Worm People 0.  In this case Eisen properly refused to be mobbed, and the attempts to demonize him backfired, so that people like Skop have come off looking ridiculous. I’m just wondering if this episode shows a pushback against cancel culture, as did Trader Joe’s refusal to eliminate the brand names of its ethnic foods.

It was just a worm joke!

h/t: John, Peter

Boudry on scientism and “ways of knowing”

July 27, 2020 • 10:30 am

It’s been a while since we’ve discussed either scientism or “ways of knowing” on this site (the two ideas are connected). I’ll reiterate my views very briefly. “Scientism” has two meanings, as Maarten Boudry notes in his piece below, but the most common non-pejorative meaning is that of science making claims outside of its ambit, something that almost never happens these days.

I’m more interested in the idea whether there are “ways of knowing” beyond those involving science or “science broadly construed” (“SBC”, i.e., any profession, including plumbing and car mechanics, that uses the empirical method and relies on hypotheses, tests, and confirmation as ways of understanding the cosmos). As far as I can see—and I’ve asked readers about this—I’ve found no way beyond SBC to ascertain what’s true about our universe.

The most common area to claim that there are ways of knowing beyond the empirical is of course religion, but theology has never found a single ascertainable truth about the Universe that hasn’t been confirmed (or disconfirmed, as in the Exodus) by empirical research. You can’t find out what’s true about the Universe by reading scripture or waiting for a revelation. Even “scientific revelations” like Kekulé’s dream of a snake biting its own tail, which supposedly gave rise to the ring structure of benzene with alternative single and double bonds, had to be confirmed empirically.

Maarten Boudy has a new blog piece that discusses these ideas, but also highlights a new paper that, he says, puts paid to the notion that there are ways of knowing beyond science. Click on the screenshot to read it. (His piece has a good Jewish title though Boudry is a goy.) As you can see from the title, Maarten tells it as it is:

Boudry, by the way, is co-author of this collection of essays, which, though mixed in quality, is generally good and gives a good overview of the “scientism” controversy. (Click screenshot for Amazon link.) The co-author, Massimo Pigliucci, absolutely despises my including stuff like plumbing in “science construed broadly,” and has said so many times. Massimo is deeply preoccupied with demarcating “science” from “nonscience,” and sees me as having messed up that distinction.

Here’s Maarten’s link to the new paper and a useful classification of four flavors of scientism:

Now yesterday I read a clever new paper in Metaphilosophy – yes, there really is a journal by that name – in defense of scientism, which follows the second strategy. The Finnish authors, known as the Helsinki Circle, present a neutral definition of “scientism”, distinguishing between four different flavors represented by the quadrant below. The four positions follow from two simple choices: either you adopt a narrow or a broad definition of science, and either you believe that science is the only valid source of knowledge or that it is simply the best one available.

The differences between “natural sciences” and “sciences” here, as Maarten wrote me, is this:

“Natural sciences” is just physics, chemistry, biology, etc.

“Sciences” includes the human and social sciences, (like “Wissenschaft” in German).

But I’d prefer the distinction to be between “science” (what is practiced by scientists proper) and “SCB”, or the use of the empirical method to ascertain truth (SCB includes the human and social sciences). Given that slight change, I’d fall into the lower-left square. The upper left square, says Maarten, is occupied only by the hard-liner Alex Rosenberg.

But never mind. Boudy and I are more concerned with the criticisms of science that fall under the rubric of “non-pejorative scientism”, and he mentions two:

The authors want to draw attention to the other three versions of “scientism”, which are more defensible but nonetheless interesting and non-trivial. In the rest of the paper, they discuss how the different interpretations of scientism fare under two lines of criticism: (a) that scientism is self-defeating because the thesis itself cannot be demonstrated by scientific means; (b) that science inevitably relies on non-scientific sources of knowledge, such as metaphysical assumptions or data from our senses.

I’ve addressed both of these, but Maarten concentrates on the second. (My criticism of [a] is that you don’t need to demonstrate a philosophical or scientific underpinning of the methods of science to accept it, because science works—it enables us to understand the Universe in ways that both enable us to do things like cure smallpox and send rovers to Mars, and to make verified predictions, like when an eclipse will occur or the light from stars might bend around the Sun). Justification of science by some extra-scientific method is not only futile, but unnecessary.

Maarten refutes (b) handily:

Here I want to focus on the second objection. Does science “presuppose” the existence of an external world, or lawful regularities, or the truth of naturalism, or other metaphysical notions? No it doesn’t. These are merely working hypotheses that are being tested as we go along. I’ve argued for this position at length myself, in a paper with the neurologist Yon Fishman and earlier with my Ghent colleagues. As the authors write:

“One does not have to assume that science can achieve knowledge of the external world. Science can merely start with the hypothesis that some kind of knowledge could be achievable. For all practical purposes, this hypothesis would merely state that there are at least some regularities to be found. This hypothesis could be tested by simply attempting to obtain empirical knowledge with scientific means. If it is impossible to achieve this kind of knowledge, then the efforts would just be in vain. But hoping that something is the case is not the same as believing that it is the case.”

Second, does the fact that scientists rely on their sense organs invalidate scientism? No, because that’s a trivial point. It’s obviously true that science could not even get off the ground without sensory data, but this input too is being refined and corrected as we go along.

All these arguments about science being “based” on some extra-scientific assumption or source of knowledge are guilty of what I call the “foundationalist fallacy”. The mistake is to think that knowledge is something that needs to be “grounded” in some solid foundation, and that if this foundation is not completely secure, the whole edifice will collapse. But this metaphor is deeply misguided, and it inevitably leads to infinite regress. Whatever ultimate foundation you come up with, you can always ask the question: what is that foundation based on? It cannot be self-evident, floating in mid-air. This reminds one of the old Hindu cosmology according to which we live on a flat earth supported by four big elephants. Pretty solid, but what are the elephants standing on? On the back of a giant turtle. And that turtle? On the back of an even larger turtle. And so it’s turtles all the way down, ad infinitum.

Boudry’s Argument from Turtles also goes, I think, for (a): if you must justify using scientific methods through philosophy, how do you justify the value of philosophy in settling such a question? But never mind. If people dismiss science as an activity because philosophy (or science itself) provides no foundation for the empirical method, I’ll just ask them, “Have you ever been vaccinated or taken antibiotics?” If they say “yes,” then they already trust in science regardless of where the method came from. (It comes, by the way, not from a priori justification, but through a five-century refinement of methods to hone them down to a toolkit that works. Remember, science used to include aspects of the Divine, as in creationism as an explanation for life on Earth or Newton’s view that God tweaked the orbits of the planets to keep them stable.)

I’ll be reading the Metaphilosophy paper (click on screenshot below to access and download it), but let me finish by self-aggrandizingly saying that Boudry does agree that SCB is part of the nexus of empirical methodology that includes “real science”

For me, an essential part of scientism is the belief in one unified, overarching web of knowledge, which was defended most famously by the philosopher Willard V.O. Quine. Take an everyday form of knowledge acquisition such as a plumber trying to locate a leak (I believe this analogy is due to the biologist Jerry Coyne). Now plumbing is not usually regarded as a “science”, but that doesn’t mean that my plumber is engaged in some “different way of knowing”. He’s also making observations, testing out different hypotheses, using logical inferences, and so on. The main difference is that he is working on a relatively mundane and isolated problem (my sink), which is both simple enough to solve on his own, and parochial enough not be of any interest to academic journals. Plumbing is not a science, but it is continuous with science, because it makes use of similar methods (observation and logical inference) and is connected with scientific knowledge, for example about fluid dynamics. The plumber or detective or car mechanic is not doing anything radically different from what the scientist is doing.

Take that, Massimo!

And here’s a reading assignment:


Recent paucity of science posts

July 12, 2020 • 8:30 am

More than one reader has mentioned to me the absence of science posts on this site, and Malgorzata, who translates them into Polish for Listy, has also noted this.  The reason is not that they take work, which they do (about three or four times the time of a “normal” post), but because I haven’t found any papers worth posting about lately. I’ve read about six, and none of them have panned out into something interesting enough to call to your attention.

All this is by way of saying that if you’re a biologist who reads the evolution literature, or a layperson who sees some publicity for a recent piece of  cool research, please call it to my attention. I’m not sure whether the absence of work that excites me (and is suitable for the readers) is due to the pandemic, which may slow things down, or it’s just a statistical quirk. Anyway, let me know if you see something interesting (with the results not too arcane, but which might intrigue the diverse readership here).


Five timely readings for the day

July 10, 2020 • 10:30 am

I have nothing to say, but it’s okay (Good morning!).  Actually, duck duties in the pouring rain (yes, I got soaked, but in a good cause), combined with overdue grocery shopping, has put a crimp in my day. But, mirabile dictu, I have five—count them, five—pieces that are worth your time to read. I’ll give a link to all of them in screenshots, though the second piece, from The Economist, is behind a paywall (judicious inquiry might yield a copy). And the indented bits are quotes from the article.

In this interview with Steve Pinker (published, in all places, at the Templeton-funded Nautilus), he discusses why Americans continue to defy social distancing and abjure masks despite the palpable health risks.  It’s largely about tribalism, but part of that involves not just solidarity with the group, but distrust of “elitist” experts.

A few bits:

We turned to Steven Pinker for help with an answer. The professor of psychology at Harvard, author of widely discussed books, including How the Mind Works and most recently, Enlightenment Now, sees the deep-seated mindset, tribalism, at work in people’s defiance of health recommendations. But it’s more than a tribalism of being with your crowd. “There’s a moralistic component to this kind of tribalism, mainly that people tend to see their own tribes as victims of some kind of oppression or harm by some rival coalition,” Pinker says, his distinctive mass of gray hair filling the Zoom screen. “They believe their actions on behalf of the group, even if symbolic, are a kind of justice, a kind of settling the score, making a statement, advancing a moral cause—as strange as that may be to those of us who are not part of that coalition, and might even have contempt for that cause. But from the inside, it always feels as if your group has been victimized, has been a longstanding victim of a series of affronts and harms for which you seek redress. And that’s common in the invented histories and myths and narratives of many peoples.”

Pinker says it can be easier to understand the effect of tribalism by putting the shoe on the other foot. “Some of the people on the political right could, indeed, ask that question of the people showing up at Black Lives Matter rallies. They’re crowded together. They’re shouting. They’re chanting. A lot of them are not wearing masks. If we imagine answering that person’s question from the point of view of our buddies on the street protesting that Black Lives Matter, we can get probably some insight, even if we have our loyalties as to which is a legitimate cause and which is the not-so-legitimate cause. But you’re asking about psychology, about what people could possibly be thinking. Well, what could they be thinking in the street, shouting slogans without a mask? What could the public health experts be thinking, telling people it’s OK to do that?”

. . .Dan Kahan, a professor of law and psychology at Yale, heads the Cultural Cognition Project at the university, which explores how cultural values shape public risk perceptions. He has shown, time and again, that the need to belong to a group, usually political or religious, overrides the facts of science. Kahan, who was unable to be interviewed, has written in Nature: “People find it disconcerting to believe that behavior that they find noble is nevertheless detrimental to society, and behavior that they find base is beneficial to it. Because accepting such a claim could drive a wedge between them and their peers, they have a strong emotional predisposition to reject it.”

Pinker agrees, but stresses that doing the right thing is never easy for anybody. “With coronavirus, it’s genuinely hard to know whether surfaces are potential vectors, whether six feet is enough or not enough, whether masks help or don’t help,” Pinker says. “From a scientist’s point of view, it’s not surprising the information would shift. That’s because our natural state is ignorance. We can only learn from data, and as the data comes in, our state of knowledge and best practices will change. But, partly because people think of experts as oracles, as opposed to experimenters and exploiters of trial and error, there’s a presumption that either the experts know what is the best policy from the get-go, or else they are incompetent and ought to be replaced. That’s opposed to what we know to be the correct situation in science—namely, no one knows anything, and you have to learn.”



A piece in The Economist describes the differences between justified complaints about racism and the view of those who, on both the Right and Left, “exploit racial divisions as a political tool.” One of the cures proposed by the anonymous author is free speech and a curbing of identity politics, as well as a list of tangible governmental policies that will reduce inequality.

A few excerpts:

This ideology also has some valid insights. Racism is sustained by unjust institutions and practices. Sometimes, as in policing, this is overt. More often, in countless small put-downs and biases, it is subtle but widespread and harmful.

But then the ideology takes a wrong turn, by seeking to impose itself through intimidation and power. Not the power that comes from persuasion and elections, but from silencing your critics, insisting that those who are not with you are against you, and shutting out those who are deemed privileged or disloyal to their race. It is a worldview where everything and everyone is seen through the prism of ideology—who is published, who gets jobs, who can say what to whom; one in which in-groups obsess over orthodoxy in education, culture and heritage; one that enforces absolute equality of outcome, policy by policy, paragraph by paragraph, if society is to count as just.

. . . The pity is that these ideas will not solve America’s problems with race. They will not eliminate inequality because they are a poor way to bring about beneficial change. Unless you can freely analyse causes and question orthodoxies you will not be able to solve problems. And unless you can criticise people and practices without fear of being called out, you will not be able to design effective policies and then go on to refine them.

The new race theory blocks progress in another way, too. The barriers to racism can be dismantled only when they are exposed—and so they must be, however painful. But the false idea that ingrained racism will forever block African-Americans at every turn is a barrier in its own right.

And, by focusing on power and division, this ideology only creates more space for some on the right to exploit race as a tool. A fundamental belief in power above persuasion frustrates coalition-building. Essential allies are not carried along, but forced along. When every transaction at work, at home, or at the school gate is seen through a prism of racial power, no encounter between different races can be innocent.

. . . . Liberals can help in America, too. Much of the material gulf between African-Americans and whites can be bridged with economic policies that improve opportunity. You do not need to build a state based on identity. Nor do you need tools like reparations, which come with practical difficulties and have unintended consequences. Economic policies that are race-neutral, which people qualify for because of poverty, not the colour of their skin, can make a big difference. They have a chance of uniting Americans, not dividing them. If the mood now really is for change, they would be politically sellable and socially cohesive.

Our Briefing lays out what some of these policies might look like. Top of the list is tackling the housing segregation that is central to America’s racial economic inequality. The reform of zoning laws and the grant of rent-assistance vouchers are the chief ingredients. That would bring many benefits, improving public services and lessening violence. More integrated housing would integrate schools too and, given America’s locally financed education, mean that more would be spent on black children. Affordable measures, including advice and modest cash grants, have been shown to boost graduation from college. A third tool is the tax system. The earned-income tax credit tops up wages of working adults. A child allowance would cut poverty. A baby bond would help shrink the wealth gap.



In this piece in Quillette, Lawrence Krauss argues (correctly, I think), that science is not structurally racist: that is, there are no longer built-in barriers to the advancement of ethnic minorities. This doesn’t mean, of course, there aren’t barriers, but that they rear up before minorities even get a chance to do science. That’s why, despite fervent efforts by every biology department I know to hire blacks and Hispanics, as well as procure minority graduate students, we aren’t succeeding. That’s not because there’s discrimination at the hiring and grad-school level, but that the pool of people reaching that stage is tiny. And that’s because there’s a lack of opportunity beginning early on: even before school starts.


During the academic strike called for by the APS [American Physical Society], it was emphasized that the proportion of black physicists in national laboratories such as the Fermi National Laboratory in Illinois (where one #strike4blacklives organizer works) is much smaller than the percentage of blacks in the population at large. It was implied that systematic racism in the profession was responsible for this, although no explicit data supporting this claim was presented.

In fact, there is a simpler explanation. There are fewer tenured black physicists at universities and laboratories because there are fewer black PhD physicists. There are fewer black PhD physicists because there are fewer black physics graduate students. There are fewer black graduate students because there are fewer black undergraduates who major in physics. This latter fact is a cause for concern. But the root cause lies in inequities that arise far earlier in the education process. These cannot be addressed by affirmative action policies at the upper levels of practicing professional scientists.

Well, affirmative action policies could help remedy the problem, but, argues Krauss, one has to abrogate the duty of science to adhere to the policy that “quality alone [is] the final discriminator.” Some will disagree with this, and for this statement Krauss has been demonized widely. I’ve argued that some form of affirmative action is useful here, but science departments throughout the U.S. have failed miserably, simply because the pool of people is so small. We need to adopt the kind of policies that the Economist article describes, and try as hard as we can to ensure equal opportunity for all from the outset. As scientists we can start doing this by doing outreach in minority communities. But that’s not nearly enough because, after we sell our field to others, we go home to our prosperous digs while the targets of our actions return to a life bereft of opportunity.

I do agree with Krauss that our main duty is to do science, and, while we should do our best to give everyone an opportunity to do science if they want to, we are not suited to be social engineers. As Krauss says:

Assistant professors of physics cannot solve racial inequality in our society. The professional responsibility of individual scientists, especially young scientists, is to do the best science they can, and to train their students as best they can. It is not to become part of a social movement, however well-intentioned that movement may be.

To see a better statement of this idea vis-à-vis official stands of universities and their academic departments, read the Kalven Report that, until recently, held sway at the University of Chicago. (Sadly, it’s dissolving as our University is deciding to take ideological stands). No, it’s not our duty to become part of a social movement, but as an evolutionary biologist whose work was funded by the public, I at least feel an onus to give back to the public by showing people how great the study of evolution is. Is that kind of outreach helpful in increasing diversity and equity? Who knows?


Several readers have sent me a multi-page list of demands, signed by hundreds of Princeton faculty, students, and staff, directed at their school as a cure for the systemic and pervasive racism they see in that institution. Although the motivation is laudable, the execution is poor, with many items almost fascistic in their requirements. This is a true document of Authoritarian Leftism.

There have been two pieces of pushback. One is by Samantha Harris, a Princeton alum writing at the Foundation for Individual Rights in Education (FIRE):

Here she describes two of the demands, one of which is clearly illegal:

The petition includes a long list of “demands,” several of which stand in direct opposition to Princeton students’ and faculty members’ rights to free speech, academic freedom, and freedom of conscience. (Notably, one of them — a demand that faculty of color receive extra pay and sabbatical time compared to white faculty — is simply illegal.) Princeton’s leadership should categorically reject these illiberal demands and make clear that the fundamental rights of its students and faculty are non-negotiable and will not be subordinated to political expediency.

The most chillingly illiberal demand in the petition asks Princeton to:

[c]onstitute a committee composed entirely of faculty that would oversee the investigation and discipline of racist behaviors, incidents, research, and publication on the part of faculty, following a protocol for grievance and appeal to be spelled out in Rules and Procedures of the Faculty. Guidelines on what counts as racist behavior, incidents, research, and publication will be authored by a faculty committee for incorporation into the same set of rules and procedures.

The threat of discipline for speech, research, and publication that is subjectively deemed “racist” by a committee of ideologically motivated Princeton faculty is an anti-intellectual, frontal assault on free speech and academic freedom at Princeton that would shut down entire avenues of inquiry, research, and discussion. How, exactly, would such a committee determine whether faculty expression or research is “racist”? A look at some recent demands for faculty discipline is illustrative.

. . .In a terrific article last month in Inside Higher Ed, University of Pennsylvania professor Jonathan Zimmerman argued that faculty must rally behind academic freedom in this historic moment — one he compared to 1950s-era efforts to purge universities of Communist-leaning faculty. Zimmerman wrote:

The biggest myth about the McCarthy period is that purges of university faculty were imposed upon an unwilling professoriate. In fact, most American faculty members embraced the campaign to remove Communist or left-leaning colleagues. They took loyalty oaths, condemned “fellow travelers” and did everything else they could to protect the university from its supposed Red enemy.

Noting that universities are “repeating all the same patterns” today, Zimmerman urged his colleagues to stand up for the academic freedom rights of unpopular colleagues:

Our university leaders are busily issuing new loyalty oaths, declaring allegiance to Black Lives Matter, and everyone else is expected to follow along. That can’t be good for our democracy, or for our universities. It’s not even good for Black Lives Matter! Like any other social movement, BLM can only benefit from a full and free discussion of it.

If met, the Princeton faculty’s demand for a committee to police speech, research, and publication for signs of racism would be the end of academic freedom at the Ivy League university. And while one would hope that any free-minded academics at Princeton would simply leave the university under such oppressive circumstances, it is more likely that, given the challenges of the academic job market (particularly for faculty with dissenting views), they would instead opt for self-censorship.

Finally, Joshua Katz, a Princeton professor of Humanities and Classics, has written a “Declaration of Independence” (presumably from the letter of demands), also outlining those parts of the demands that would nearly destroy his school as a high-quality University.

One quote and then I will leave you to your reading. But at least look first at the letter of demands. What’s remarkable about that letter is that these days it is so unremarkable: it’s a boilerplate of every grievance of the offended.


Indeed, plenty of ideas in the letter are ones I support. It is reasonable to “[g]ive new assistant professors summer move-in allowances on July 1” and to “make [admissions] fee waivers transparent, easy to use, and well-advertised.” “Accord[ing] greater importance to service as part of annual salary reviews” and “[i]mplement[ing] transparent annual reporting of demographic data on hiring, promotion, tenuring, and retention” seem unobjectionable. And I will cheerfully join the push for a “substantial expansion” of the Mellon Mays Undergraduate Fellowship Program, which encourages underrepresented minorities to enter PhD programs and strive to join the professoriate.

But then there are dozens of proposals that, if implemented, would lead to civil war on campus and erode even further public confidence in how elite institutions of higher education operate. Some examples: “Reward the invisible work done by faculty of color with course relief and summer salary” and “Faculty of color hired at the junior level should be guaranteed one additional semester of sabbatical” and “Provide additional human resources for the support of junior faculty of color.” Let’s leave aside who qualifies as “of color,” though this is not a trivial point. It boggles my mind that anyone would advocate giving people—extraordinarily privileged people already, let me point out: Princeton professors—extra perks for no reason other than their pigmentation.

“Establish a core distribution requirement focused on the history and legacy of racism in the country and on the campus.” There would be wisdom in this time of disunity in suggesting (not, in my view, requiring) that students take courses in American history and constitutionalism, both of which almost inevitably consider slavery and race, but that is not the same thing. Not incidentally, if you believe anti-blackness to be foundational, it is not a stretch to imagine that you will teach the 1619 Project as dogma.

. . . “Constitute a committee composed entirely of faculty that would oversee the investigation and discipline of racist behaviors, incidents, research, and publication on the part of faculty… Guidelines on what counts as racist behavior, incidents, research, and publication will be authored by a faculty committee for incorporation into the [usual] set of rules and procedures.” This scares me more than anything else: For colleagues to police one another’s research and publications in this way would be outrageous. Let me be clear: Racist slurs and clear and documentable bias against someone because of skin color are reprehensible and should lead to disciplinary action, for which there is already a process. But is there anyone who doesn’t believe that this committee would be a star chamber with a low bar for cancellation, punishment, suspension, even dismissal?

As Andrew Sullivan would say, “See you next Friday.” Actually, I’ll see you this afternoon and tomorrow morning.

h/t: Merilee, pyers, Paul

Paper retracted for title and wording: “Where there are girls, there are cats.”

July 9, 2020 • 1:30 pm

I haven’t seen the original version of this paper in Biological Conservation, which investigates the correlates of feral cat density in 30 Chinese universities, but a piece in Retraction Watch, below, implies that the title (and perhaps other bits of the paper) caused its retraction by Elsevier (the publisher) until until it was changed. The indictment: sexism—in particular, the frequent use of the term “girls”.

Retraction Watch, and the last link above, imply that the sticking point was indeed the paper’s title:

As promised, Biological Conservation has replaced a controversial paper on feral cats in China whose cringeworthy title — “Where there are girls, there are cats” — prompted an outcry on social media that resulted in a temporary retraction.

The new article boasts a different, non-gendered title: “Understanding how free-ranging cats interact with humans: A case study in China with management implications.” But it makes more or less the same point: Where there are women, there are more cats.

Cringeworthy? Well, why not call it “Where there are women, there are more cats”? Who’s running the railroad at RW?

The new ungendered paper (click on screenshot):

The abstract (with the sex aspect in bold, my emphasis):

The growing population of outdoor free-ranging cats poses increasing threats to biodiversity. While those threats are now well recognized, how human-cat interactions contribute to shape population dynamics have been overlooked. In this study, we explore major variables associated with the distribution of free-ranging cat density in 30 universities in Nanjing, Jiangsu Province, China. We specifically focus on possible even greater care devoted by women to the free-ranging cats. We found that, as expected, the density of feeding stations is positively associated to the density of free-ranging cats. More interestingly, the density of male students versus female students seemed to be non-randomly associated with the distribution of cats among universities. An online questionnaire confirmed that women were more concerned about the living conditions of free-ranging cats than men in China. Finally, a socialization test focusing on 27 free-ranging cats conducted by female and male observers suggests that cats may have the ability to adopt a friendlier behavior with female students. Our result suggests that human-cat relationships can be understood using multiple angles, including population dynamics, behavioral ecology and conservation psychology. Such a better understanding of human-cat interactions is necessary to develop relevant population management in urban context.

And a bit of the (new paper):

The TIRM model was selected for the analysis and we used the corresponding estimated density of the cats in each campus in the following analysis (Supplementary Table S2). The Pearson correlation test showed that the density of cats was significantly correlated to the student density (N = 30, r = 0.63, p < .001), to the feeding station density (N = 30, r = 0.85, p < .001), to the women density (N = 30, r = 0.78, p < .001) and also to the proportion of women (N = 30, r = 0.65, p < .001). However, it was not correlated to the percentage of greenery coverage of each campus (N = 30, r = 0.13, p = .49), to the density of men (N = 30, r = 0.26, p = .15) or to the survey season (N = 30, r = −0.07, p = .72). The percentage of total explained variance of those factors were ordered as follows: feeding station density (34.06%) > women density (22.44%) > proportion of women (17.78%) > student density (16.65%) > men density (6.52%) > season (1.44%) > percentage of green coverage (1.11%).

And the results from a questionnaire:

The 2038 online questionnaires showed that women had fed or rescued outdoor free-ranging cats more often than men (χ2 = 94.692, p < .001, df = 1, Fig. 1). Similarly, women tend to feed outdoor free-ranging cats more regularly (χ2 = 19.345, p < .001, df = 1, Fig. 1).

All in all, it looks like the authors found a statistically significant correlation between the density of feral cats and the density of women, and they could explain at least some of it, at least in theory, by the tendency of women to rescue and feed feral cats more often than men.

But that’s not good enough. Retraction Watch, which seems outraged by the original title, along with (of course!) social media, applauds the change:

The journal also published an editor’s note — in which they manage to keep the search engine optimization value of “Where there are girls, there are cats,” while disclaiming the title — explaining its actions. The editor, Vincent Devictor, didn’t respond to our request for comment when we reported on the withdrawal, and he is joined on the editorial by Danielle Descoteaux, of Elsevier, which publishes the journal.

Step one: blame language barriers for a poor decision that, as any editor should admit, falls squarely on their shoulders.

Was that decision really that poor? Or was it the “social media outcry” that made the journal retract the paper? You know the answer.

In truth, I am not that bothered by the title, which is pretty cute and, given the data, seems accurate as far as it goes—though had I written it I would have said “women” instead of girls. Nope, the title is dumbed down and gender-purified until it’s just the usual anodyne and tedious title we see so often. And the authors, of course, had to issue an apology:

. . . . we did not realize the topic is so sensitive, although at first we actually have tried our best to wirte [sic] the words… I firstly want to declare that I have not any sexism or even any thought of it, probably it is an English expression and culture difference that misleading readers since we are not native English speaker. For the title, may be catchier in our current version, it is like to say ‘more girls, more cats?’, just to catch readers that maybe cat density is related to sex ratio? In Chinese, it is very easy to understand and accept. I really don’t understand why human sex cannot be discussed in a paper, as we discuss more in animals research, or it is a culture difference…Not sure… 3, Actually in this paper, we just want to show a phenomenon, a point, a possible correlation, that cat density may be related to human social structure especially the sex ratio. I know correlation sometimes is not causation, but sometimes it is. Someone said feeding station is another more influencing factor, but who made these feeding stations? AT least from our observation, most are females in both universities and communities. Tell them more the fact that free ranging cat is invasive and affects biodiversity significantly and don’t feed them is very important. We have not any suggestions or ideas to control human sex, if I did not misunderstand some readers’ thoughts. Our suggestion is just to tell them the possible impact of feeding behavior to free ranging cats.

oooookay. . . .  so we live in a world where a title like that caused a social media outcry. Do these keyboard warriors ever rest? Yes, perhaps the use of the term “girls” was unwise, but really, people?

To wit:

Translation: “I used the term ‘girls’ which is regressive, counterrevolutionary, and contrary to the teachings of Chairman Meow.”

“This is the nice thing about science . . . “

May 6, 2020 • 12:30 pm

by Greg Mayer

Mark Mulligan, a vaccine researcher at NYU, was asked by NBC News if he was optimistic about the prospects for the covid-19 vaccine he is working on.  He replied,

This is the nice thing about science. You don’t have to have faith or belief.

(NBC’s transcript, for some reason, edited out “. . . nice thing about . . .”.)

Genetic ignorance in the service of ideology

April 22, 2020 • 12:00 pm

Angela Saini is a British science writer who belongs to what I call the Cordelia Fine School of Science Journalism (CFSSJ): a school whose members have an explicit ideological bias that colors all of their popular writing. In the case of Fine, her ideology is that there is essentially no evolutionary/genetic difference between the brains and neurology of men and women, and so any behavioral differences we see are of purely social origin. Further, hormones play little or no role in behavioral differences between the sexes. Fine’s motive is good—to reduce sexism and bias—but her modus operandus is not, for it involves misrepresenting science.

To buttress Fine’s ideology, her books aim at debunking every study that contradicts her preconceived thesis, even though there is now convincing indication of not only genetically based behavioral and morphological differences based on hormones, but also of differences in the brain. In contrast, Fine goes easy on studies that support her thesis.

In other words, the CFSSJ is characterized by tendentious science writing and confirmation bias, with the bias occurring in how studies are discussed. In the case of Angela Saini, her ideological bias is that all races are equal in any important aspect of biology, and that investigation of differences between races (or, as I call them, “populations” or “ethnic groups”) is liable to play into what she calls “scientific racism”. Ignore the fact that scientists have been trying for decades to debunk the misuse of science in buttressing racism, and most journalists, particularly those with little knowledge of genetics, haven’t been particularly helpful. Some, like Carl Zimmer, know their onions, while others, like Saini, apparently can’t grasp the fundamentals.

I’ve been struck, especially in the CBC interview with Saini shown below, by her willingness to make insupportable statements about differences between groups. I haven’t yet read her book on the topic, Superior: The Return of Race Science, as our library is closed and I don’t want to pay to support ideologically-based biology. But I’ve read other writings of hers, reviews of her books, both pro and con, as well as listened to YouTube videos and lectures. None of this has disabused me of the notion that she’s a member in good standing of the CFSSJ. Further, as we’ve discussed here, she’s misrepresented the situation at University College London by asserting that the scientists there have  papered over the college’s history of eugenics and racism.

I’ll give you just one example of how Saini misrepresents the truth in the service of ideology. I was especially concerned about this one because the misrepresentation crops up frequently in discussion of genetics and “race”, and it’s time that people get the issue clear.

The error comes from an interview Saini did for the CBC’s “Quirks and Quarks” show, which you can hear by clicking on the link below. There’s also a partial transcript: 

Here’s just one Q&A from that show, but it’s an important one:

Let’s move into the modern era then. Biologists have come up with a really strong scientific critique of the idea of race. Can you take me through that? 

Well, for 70 years since this consensus after the Second World War, all that biology has done is reinforce the fact that we are so similar. We imagine the genetic differences between racial groups.

For example, I am of Indian origin. My parents [were] born in India. But if I were to randomly pick a South Asian person on the street and randomly pick a white, Canadian person on the street and test their genomes, it’s perfectly statistically possible for my genome to have more in common with a white person than with the Indian person. That’s how almost complete that overlap is. So we are incredibly similar as a species, and the vast majority of difference that we see is accounted for by individual difference.

Now I’ve tried to parse her statement in a way that it would be correct, but I can’t. In fact, the only way you can say that there’s any validity to her claim of no difference between the South Asians/white Canadians and South Asians/South Asians comparison is to construe “perfectly statistically possible” to mean that you might be able to find one or a couple of South Asians who, throughout their genomes, were more similar to some Canadians than they were to other South Asians. But you will almost never find that. We know this from the genetic data that already exist. You could equally well assert that it’s “perfectly statistically possible” for all the oxygen molecules in your room to move to the other side of the room at once, suffocating you. The error is taking what is possible and making people think that this is what’s common or probable.

In fact, all the genetic data we have shows that Saini’s implications about genetic similarity are wrong. If you want to validate her claim, you would have to look at gazillions of nucleotide bases in the DNA sequences of white Canadians and South Asians (I presume Saini means Indians, as she’s of Indian descent), and show that, on average, the proportion of DNA sites that had identical bases in Canadians vs. South Asians was about the same as the proportion of DNA sites that had identical bases in two randomly selected South Asians.

And that, according to the data we have, is not the case. Because of genetic similarities between populations that are spatially (and historically) contiguous, if you find identical bases at one DNA site, it becomes more likely that you’ll have identical bases at other sites. This is easily shown by combining DNA data from different regions of the genome (different “genes” or “SNPs”) to conduct a cluster analysis of overall similarity. And when you do that, you find that populations cluster based on history and geography. Assuming that, say, you’re not sampling a recent Indian immigrant to Canada as a “white Canadian”, or a Candian who lives in Mumbai as a South Asian, you can pretty well diagnose someone’s geographic ancestry—their “population”—from their genes. Here’s an example from 2015 on a very small scale, showing clustering within the British Isles (click on screenshot to access the paper):

Heres a diagram of the clustering, showing how easily someone’s population can be diagnosed from a large sample of DNA bases. Look, for example, at the demarcation between Devon and Cornwall—populations separated only by a river!

What this shows is that if you use information from the whole genome, people’s origins can be largely diagnosed, even on this small scale that used half a million DNA sites—a small fraction of all the DNA sites, which number 3 billion in humans). If you looked at South Asia versus white Canadians, you’d get even more differentiation. Saini’s claim that it’s likely or probable that you could find more similarity between a Canadian and South Asian than between two South Asians is palpably false.

I think where Saini went wrong is that she committed what’s known as “Lewontin’s fallacy,” named after my Ph.D. advisor and discussed in a paper by the geneticist A. W. F. Edwards. What Lewontin originally asserted, correctly, was that if you take all the genetic variation present in the human species, and apportioned it among individuals, among populations within a so-called “race”, and then among “races” (defined as the classical “races”), you find that of all the variation, 85% can be found among individuals within a population, 8% among populations within a “race”, and only about 6% between “races”. In other words, individuals within a population contain nearly all of the existing genetic variation of our species, and when you add different populations or different races, you don’t beef up the variation much more.

Lewontin took this to mean that there are no such thing as genetically differentiated races (as I said, I prefer, because of the historical freighting of “race”, to use “ethnic groups” or “geographically differentiated populations”). And that’s where he made his error. Lewontin is right if you look at each gene separately and then average the apportionment of variation among different genes. But genes among populations are not independent. As I said, if you’re different at one gene among ethnic groups, you’re more likely to be different at other genes as well. In other words, the structure of genetic variation, because of history and evolution, is correlated. I quote Wikipedia on Edwards’s refutation of Lewontin’s conclusion:

Edwards argued that while Lewontin’s statements on variability are correct when examining the frequency of different alleles (variants of a particular gene) at an individual locus (the location of a particular gene) between individuals, it is nonetheless possible to classify individuals into different racial groups with an accuracy that approaches 100 percent when one takes into account the frequency of the alleles at several loci at the same time. This happens because differences in the frequency of alleles at different loci are correlated across populations—the alleles that are more frequent in a population at two or more loci are correlated when we consider the two populations simultaneously. Or in other words, the frequency of the alleles tends to cluster differently for different populations

In Edwards’ words, “most of the information that distinguishes populations is hidden in the correlation structure of the data.” These relationships can be extracted using commonly used ordination and cluster analysis techniques. Edwards argued that, even if the probability of misclassifying an individual based on the frequency of alleles at a single locus is as high as 30 percent (as Lewontin reported in 1972), the misclassification probability becomes close to zero if enough loci are studied.

The cluster analysis mentioned by Edwards was used in the analysis of the British populations given above.

And if the misclassification probability of an individual becomes close to zero when you add more bits of DNA, as it does, then Saini is simply wrong. Yes, races are not nearly as genetically differentiated as early biologists thought they were, and yes, most of the variation in genes can be found in single populations and not among populations or “races”. But you can still genetically diagnose people as to ethnicity by looking at a big chunk of their DNA. South Asians will be more similar to other South Asians than to a white Canadian.

Most of the bits of genome used in these analyses don’t really do much, or have no functional significance in geographic differences in behavior, morphology, or physiology. But populations also differ in meaningful “adaptive” ways because of natural selection. Lactose tolerance and oxygen-carrying ability of the blood are two famous traits, and this paper by Sarah Tishkoff gives many more. Here’s a figure from that paper. It clearly shows that different populations differ in adaptive traits:

Now just because you can diagnose someone’s ethnicity or geographic origin from their genes does not in any sense buttress racism. All it shows is that our genomes reflect our historical and evolutionary ancestry. Saini, in her desire to show that there are no differences, doesn’t seem to realize that the genetic differences used to diagnose people do not place any races above others—there’s no support for any inherent superiority or inferiority of groups. But rather than admit the truth about genetic difference and then say it doesn’t matter morally or politically, Saini would rather throw out the inconvenient data. This is the hallmark of the CFSSJ: if the data go against your ideology, either ignore them or deny them. Or misrepresent them.

This has already gone on too long, but I’ll support my thesis about Saini’s ideologically based science by directing you to another review of Superior: The Return of Race Science, as well as to an Amazon review which is remarkably thorough. Both reviews discuss Saini’s insupportable and misleading claims about genetics. Looking over her claims (another is that there is no genetic variation within populations affecting cognition; see quote from Amazon review below), I can only conclude that in many places crucial to her thesis, she doesn’t know what she’s talking about.

The first requirement for writing sgood cience journalism or popular science books should be this: be sure you understand the science. Or, as Davy Crockett said, “Be sure you’re right first, and then go ahead.”


From the Amazon review of Superior:

On page 221, Saini says, “The question of whether cognition, like skin colour or height, has a genetic basis is one of the most controversial in human biology.” To be clear, this sentence is referring to the causes of individual variation in cognition, not the causes of differences between group averages. The question of whether or not group differences have a genetic basis is indeed controversial, but in 2019, making such a statement about the heritability of individual variation is equivalent to saying that it’s controversial whether or not global warming exists. Ideas such as the existence of global warming or the heritability of cognitive ability are controversial among some political activists, but among professionals in the relevant fields, these questions have been regarded as settled for more than twenty years.

If she really says that on page 221, it’s a howler. The heritability of IQ, for instance, is around 50%, which means that of the variation of IQ scores within a population, half of that variation is due to variation in genes.

A pro-science ad from Pfizer: “When science wins, we all win”

April 16, 2020 • 8:30 am

You will perhaps pooh-pooh me for putting up this ad, which I saw on the news last night, but I don’t think you should. Sure, it’s produced by a “Big Pharma” company—Pfizer—but its message is still on the money. Just listen to the words and forget that, in the end, it’s advertising.

If it just makes people realize, as New York Governor Andrew Cuomo said, when speaking to CNN, “We’re talking about a reopening that has a public health plan and an economic plan totally coordinated. Our behavior has stopped the spread of the virus. God did not stop the spread of the virus. And what we do, how we act, will dictate how that virus spreads.”

Even Big Pharma can speak the truth. Or would you prefer that they produced an ad extolling the power of religion?

Matthew’s theory, which is his, about why Covid-19 and other viral infections often reduce one’s sense of smell

April 1, 2020 • 11:52 am

Matthew tweeted his new theory, which is his, about why Covid-19 patients very often experience “smell blindness”, technically known as anosmia—the loss of one’s sense of smell (which of course also reduces one’s ability to taste). I asked him if he wanted to post it here, and he’s rewritten it so it’s understandable by the science-friendly layperson. And so, without further ado:

A hypothesis to explain why the Covid-19 virus affects the sense of smell in some people

By Matthew Cobb


In a recent study by King’s College, London of 579 people who reported having a positive Covid-19 test, 59% said they had reported a loss of smell or taste. This is not unique to Covid-19 – many other viruses can cause the same effect. It has never been quite clear how this occurs. The great amount of attention being paid to Covid-19 has helped reveal one possible mechanism.

We smell volatile molecules, but we don’t directly detect them in the air – our smell neurons would shrivel up and die. Our neurons are protected by a layer of mucus, and the smell molecules have to get through that.

The chemical structure of most smells means they are what is known as hydrophobic – they won’t dissolve easily in water, such as that found in the mucus. It is widely thought that the smells are transported by rather mysterious chaperones called olfactory binding proteins (OBPs).

These molecules are secreted into the mucus by cells called Bowman’s cells in the olfactory epithelium – the layer of skin, high up in the roof of your nasal cavity, which is where you smell things. Many scientists think that OBPs deliver the odour to the receptor on the neuron, and then appear to be taken up by cells called sustentacular cells which lie next door.

A paper that appeared a few days ago suggests that our olfactory neurons don’t express the ACE proteins that are the virus target, and that disruption to our neurons is therefore not the cause of anosmia. However, other cells in the olfactory epithelium, the sustentacular cells and the Bowman’s cells that produce OBPs, do express the ACE protein. Both these cell types are involved in the way that OBPs work.

If the virus is attacking these cells, then the metabolism of OBPs, and thereby the balance of detection of molecules will be altered. This may explain the widespread reports of anosmia following covid-19 infection, and, in some cases like that of the science journalist Adam Rutherford, who had symptoms of covid-19,  hyperosmia (increased sensitivity). Sustentacular cells are also electrically active in newborn mice, perhaps indicating a more complex function for these cell types.

All this suggests that the return of normal olfactory functioning in patients with covid-19, or other coronaviruses, which may also cause these effects, probably depends on the time it takes for the Bowman’s cells and the sustentacular cells to recover.

A simpler explanation – advanced by @stevenmunger on Twitter in response to this – is that infection of these specific cell types merely causes inflammation, which alters tissue function. There may be other hypotheses, too. And some scientists don’t agree that OBPs play much of a role at all in olfaction. “For example, although humans have a number of genes that encode for OBPs, only one kind has so far been identified in the human olfactory epithelium. We clearly need to understand more about this aspect of how we smell.”

Whatever the exact mechanism involved, as Prof Tim Spector of King’s College said: “When combined with other symptoms, people with loss of smell and taste appear to be three times more likely to have contracted Covid-19 according to our data, and should therefore self-isolate for seven days to reduce the spread of the disease.”

For advice on living with anosmia:

BBC report of the King’s College study:


Brann et al (2020) – Gene expression in olfactory epithelium, on covid-19 and entry:

Strotmann & Breer (2011) – OBPs and sustentacular cells

Vogalis et al (2005) – Electrical activity in sustentacular cells

Badonnel et al (2009) – OBPs secreted by Bowman’s cells