I suppose the “fair use” policy allows magazines and newspapers to quote this website without permission, but it would have been nice had the New York Times asked me before quoting part of my post about Susan Dominus’s wonderful NYT Sunday Magazine piece on the mixed-up twins of Bogotá. (Do read her piece if you get a chance; it’s a fantastic story.)
At any rate, my quote is in the magazine’s letter’s section that appeared yesterday, with the excerpt running first. I’m of course pleased at that, but editors normally ask permission and seek verification before publishing letters. Here’s what they quote.
Ethics dictates that we can’t do the kind of experiments on humans that we can on flies and cows: separating individuals at birth and seeing how much difference in behavior and appearance can be created by rearing siblings (identical or fraternal) in different environments. Data so far show that a surprisingly large amount of variation in human behavior rests on variation in genes, but these studies aren’t perfect. Still, they should give pause to those who believe (often based on political ideology) that genes don’t play much of a role in the diversity of behavior among individuals in the human population. Jerry A. Coyne, in a post on his blog, Why Evolution Is True
I like the fact that they include my words on ideological opposition on genetic determination of human behaviors—as some keyboard-warrior atheists have adopted this misguided stand on political grounds—but Earth to NYT: it’s not a blog!
There are several other letters, but only one is of interest:
What’s not often considered in studies of identical twins reared apart is whether identical twins reared together actually grow up to have more differences from each other than they might have had if they had been reared apart but in very similar circumstances or as an only child. Twins raised together need to find some interests or achievements that are unique to them and that distinguish them from their twin. Twins raised apart or alone would have much less motivation to be different from ‘‘themselves’’ in order to be noticed and praised, and thus they would be less driven to pick interests or modes of expression that differ from their twin’s and perhaps from their own genetically driven inclinations. You could speculate that epigenetic effects may also influence or even develop from these differing behaviors and the natural desire of an identical twin to be somewhat less than completely identical in the eyes of the rest of the world.raflei00, posted on nytimes.com
I’m not aware of any evidence that identical twins raised together are actually more different than such twins raised apart; I suspect that evidence exists, but hasn’t been examined because the more important issue is that the similarity of identical twins raised apart (compared to fraternal twins raised together or apart) gives us important information about the genetics of behavior, “IQ” (whatever that may be), and physiological and morphological traits.
Granted, identical twins raised apart may sometimes be put in more similar environments than are normal siblings separated at birth (I’m not sure if this is the case, but the issue has been bruited about), so that environmental similarities may be conflated with genetic ones. But one fact stands: if identical twins raised apart are substantially more similar than are fraternal twins raised together, that suggests a big genetic component to variations in human behavior. After all, it would be a misguided scientist (or an ideologue) who would claim that the environments of identical twins raised apart were more similar than that of fraternal twins raised together!
Finally, as far as I know, identical twins raised together often seem to seek to be similar: dressing alike when they’re old enough to have a choice, and hanging around together. These issues wouldn’t apply for twins raised apart, and would militate against the thesis of the letter-writer above.
As for the speculations on “epigenetic effects”, well, that’s irrelevant to the author’s otherwise interesting speculation, for it involves the effects of different environments on the twins’ DNA—something that probably doesn’t happen, and—as it would disappear in their children—would be of minimal interest.
h/t: Diane G
Nonexistent. Like a three-bob bit, a can of tartan paint or a left-handed spanner.
Damn, mouse-o!
Left-handed spanners exist, they’re just identical to right-handed spanners.
Three-bob bits would be simple to manufacture. I have a couple of perfectly genuine legal tender three-dollar notes.
Tartan paint, otoh, is, as you say, non-existent and non-realisable.
And this is the wrong thread 😉
cr
When you send a trainee down to stores for a left-handed spanner, stores are out of them. They do have the long stand though, and will send someone up to deliver it when they can.
This is the wrong thread? Notches on the flats? Or NPT?
What about left-handed mugs and cups? 😉
I have several, in either orientation.
To date, I am not aware of an ISO standard which declares if the handedness of the mug-body, mug-handle and mug-decor assembly is to be described from the drinker’s point of view, or the person watching the drinker.
Just for information, do you know how many conventions there are for describing the location of landscape features?
I think the key concern would be whether the opening of the cup was on the top or bottom. I only purchase top opening cups myself, but that’s just me.
Topologically there is no difference. However in practical terms, the bottom-opening ones are preferred in the Southern Hemisphere.
cr
I’m glad you mentioned that. As I recall, as a cruise ship crosses the equator, there is often a ceremony conducted to mark the transition. The flipping of cups has got to be part of that.
That’s the simple bit. The tricky bit is flipping the boat. 😉
cr
Correct. That really gets the crew and staff scrambling. 😎
If not a blog, what is WEIT?
You must be new – our host refers to it as a website.
Well, I am not new, but I have basically the same question. What’s the issue with the word “blog”?
Personal distaste. ‘Nuff said. (I.e., please don’t follow with the definition of “bl*g.”
Derek the first–you will learn more about our host’s humorous personal quirks from reading “Da Roolz,” which can be found on the sidebar above. Not for nothing did Dawkins commend this website for its “idiosyncratic charm.” 🙂
I think you mean “more similar”.
Indeed! I’ve fixed it thanks!
Exactly and exactly! That is, my favorite part of the excerpt they used (and perhaps the reason they chose it) was the allusion to political ideology; and the only other letter of interest was the one about identical twins raised together being possibly more different than separated twins. I imagine the epigenetic speculation was in response to the discussion of epigenetic effects in the original article.
IME, I’ve known at least a couple of sets of identical twins in which there did seem to be a strong attempt by at least one of the pair to distinguish herself from her sister; though at other times they did enjoy indulging in the sorts of mischief only such pairs can carry out.
sub
-liminal
-luminal
I don’t know what science there is on the effect of twin competition. But I do know that the one pair of identical twins I know – among my best friends since I was a teenager – exemplified the twin competition
hypothesis. One twin especially went to pains to really be different from his twin – dressing fairly theatrically, being outgoing and positive and artsy, as against his twin who he saw as far too square and conservative. The wilder of the two twins told me once or twice that being different from his twin was part of his motivation.
FWIW…
My twins aren’t identical, but holy shit are they competitive. Drives me nuts.
As a parent of twins one of the most common questions I have been asked when people see the twins for the first time is, “Oh, are they identical twins?” Since one is male and the other is female this question used to leave me with a confused look on my face as I tried to understand what was happening.
I’d be so tempted toward a snarky answer…
Even though it is mentioned briefly in Susan Dominus NYT article, it would perhaps be appropriate to repeat it here, that Nancy Segal has written several books on this topic, among them:
Entwined Lives: Twins and What They Tell Us About Human Behavior
Born Together – Reared Apart: The Landmark Minnesota Twin Study
Especially the book about the Minnesota Twin study is incredibly comprehensive (as far as I can judge), and summarizes and describes all the published research originating from the study.
One interesting aspect is the fact that monozygotic and dizygotic twins overlap in how similar they appear, and that the identity sometimes is mistaken. At least it was before genetic tests were common.
This opens up the opportunity to test the hypothesis, (sometimes put forward by critics) that the increased similarities between monozygotic twins is based upon the fact that they are treated more alike because the look more alike.
And the answer by the data is, if I remember correctly, a clear no.
I can highly recommend the book, even though it leans more heavy towards the science part, then the human stories behind.
From https://wordpress.org/about/:
“There is also a service called WordPress.com which lets you get started with a new and free WordPress-based blog in seconds”
WordPress call their own service a blog. I think it’s time you capitulated, Jerry 😉
What’s wrong with a blog anyway, especially a good one?
See comment 2. And read Da Roolz.
(And don’t think comments just like yours haven’t been posted many times before.)
Well, it did credit you and give a link, i.e. linking to the source. I believe this is common practice that doesn’t require asking for permission so long as whole articles have not been reprinted but only excerpts.