Evo psych error roundup
An influential group of biologists, psychologists, and other busybodies has for decades promoted the idea that the social sciences should be grounded in the ideas of evolution, that human behavior should be predicted from estimates of what evolution would do. The idea has been heavily promoted from the 1970s, when it was called sociobiology, until today, where it’s called evolutionary psychology (evo psych for short), but little in the way of compelling evidence has been produced. Today, we’ll focus on some less than compelling evidence.
Exhibit A: One common (and characteristically offensive) claim among evopsychers is that your mother’s mother will spend more time caring for you than your father’s mother because — naturally enough — your father’s mother isn’t evolutionarily certain that you have her DNA, since your mother could have been impregnated by any one of tons of guys. The data does indeed seem to bear this out, but sadly this is no win for the evopsychers, since there are some perfectly competent alternative explanations: kids are usually primarily raised by their mothers and its not surprising that those mothers will look to their mothers for help. (via Jeremy Freese)
Exhibit B: In 1995, Christenfeld and Hill argued that since fathers were so unsure if kids were really theirs, evolution would ensure that kids looked more like their fathers than their mothers, so that they wouldn’t be abandoned by deadbeat dads. And, sure enough, they had some students rate whether kids looked more like their father or mother and found that they looked more like their father. Robert French later redid the study, only to find that he couldn’t replicate the results. Oops. (via Mark-Jason Dominus)
Exhibit C: In 1993, Devendra Singh spent months pouring over old copies of Playboy — for science, of course. He set about measuring the waist-to-hip ratios of Playboy models and Miss America winners, concluding that they had maintained relatively constant — approximately .70 — even as the models had gotten thinner over the years. He argued that men were evolutionarily wired to find this “hourglass shape” attractive. The result was quoted in just about every evopsych textbook and news article since. Well, Jeremy Freese and Sheri Meland checked the numbers and found — once again — that none of it was true. There have actually been statistically significant changes in waist-to-hip ratios over time. (original article)
Andrey Fedorov May 19
Wow, it seems like you almost have a personal vendetta against evo psych, Aaron… just because two studies (B,C) were badly conducted doesn’t mean one should discount the entire field.
And I’m not sure what exactly the point of (A) is … “One common (and characteristically offensive) claim among evopsychers is that your mother’s mother will spend more time caring for you than your father’s mother”
You’re arguing against what you came up with as “one common claim”? Really? That’s funny, from all I’ve heard of evo psych, I never heard that claim, but how about the common claim that mothers are more likely to take care of the children than fathers, who are more likely to go out and “provide for the family”? Why is this consistent across the vast majority of cultures?
aaronsw May 22
I think evo psych is bad science with good PR; it’s nothing personal and I wouldn’t really call it a vendetta. I don’t think a couple bad studies should discount the field and never said so. If you want to see why the field is bogus, there are many, many good books and articles on the subject. This post was simply criticizing three particular studies. I happened to group them together because I learned about them around the same time and they were all evo psych studies.
The claim in A is not simply something I came up with (nor is its critique). As the linked-to article notes, it is “the primary case study that Cox [the evo psych author under review] offers in exploring the potential usefulness of an evolutionary approach”. Similarly, I heard the argument in Psych 101 at Stanford and believe I saw it in Pinker’s textbook. I haven’t done a careful study, but I wouldn’t be surprised if it was in many or most of the relevant introductions, as C is.
As for your contention that “mothers are more likely to take care of the children than fathers … across the vast majority of cultures”, could you please provide a citation? The anthropological evidence I’ve seen finds that while many cultures have a gender-based division of labor, the patterns for which gender gets assigned which task are much less strong.
Jamie McCarthy Aug 29
It’s indisputable that “mothers are more likely to take care of the children than fathers … across the vast majority of cultures.” I mean, I guess you could try to dispute it, feel free to start presenting evidence, but it’s so well-established that your even questioning it makes me question your objectivity.
If you really need a citation, Pinker cites D.E. Brown, “Human Universals,” 1991 (on p. 346 of “The Blank Slate”)… but c’mon.
Didn’t you even grant this point already? Look back at your Exhibit A. “your mother’s mother will spend more time caring for you than your father’s mother… the data does indeed seem to bear this out.” You suggest this might not have anything to do with evolution because “kids are usually primarily raised by their mothers”… um, yes. Precisely. Across the vast majority of cultures. Now why would that be?
aaronsw Sep 12
I didn’t mean to question the claim; I just thought it would be interesting to see a study on the topic. Human Universals is a somewhat sketchy book, rather outside the social anthropology mainstream.