You bring up very interesting points!

“Black Africans” were once a minority of Africans, who were more successful than their competitors and spread. I’m not sure how this relates to the Bantu expansion [1], but the relatively more ancient origins of the Bushmen, Pygmies, and Aboriginies is discussed by Nick Wade in Before the Dawn [2,3].

Scientific genetics have let us begin to see the world as it really is, in spite of the myth makers of the 1970s (who denied such things as races existed [4]) and the 19th century (who viewed them as platonic forms [5]).

[1] http://en.wikipedia.org/wiki/Bantu_expansion
[2] http://www.tdaxp.com/archive/2007/05/02/review-of-before-the-dawn-by-nicholas-wade.html
[3] http://www.amazon.com/Before-Dawn-Recovering-History-Ancestors/dp/1594200793
[4] http://en.wikipedia.org/wiki/Lewontin%27s_Fallacy
[5] http://en.wikipedia.org/wiki/The_Passing_of_the_Great_Race

Origins of black Africans

Very interesting!

It would be interesting to know how much of visible human variation (eye color, height, hair patterning, etc.) is the result of sexual selection.

Likewise, to what extent this sexual selection is the result of mate choices of men by women, as opposed to mate choices of men by the father’s of women, or even differential rates of rape victimhood, would be interesting to know.

Sexual selection of women rather than “the usual processes of evolution”

Thanks for the link!

From the article:

Frost’s theory is also backed up by a separate scientific analysis of north European genes carried out at three Japanese universities, which has isolated the date of the genetic mutation that resulted in blond hair to about 11,000 years ago.

The hair colour gene MC1R has at least seven variants in Europe and the continent has an unusually wide range of hair and eye shades. In the rest of the world, dark hair and eyes are overwhelmingly dominant.

Just how such variety emerged over such a short period of time in one part of the world has long been a mystery. According to the new research, if the changes had occurred by the usual processes of evolution, they would have taken about 850,000 years. But modern humans, emigrating from Africa, reached Europe only 35,000-40,000 years ago.

The “10,000 years ago” formula is one that keeps turning up. About that time, humans began living in cities, and indeed were able to live in large-scale societies even before there were farms. Modern humans and those just 15,000 ago may be behaviorally quite different from each other. [1]

I’m not sure what “the usual processes of evolution” are that the article mentions, but I’m guessing they mean genetic drift. Natural selection became politically incorrect in the 1960s, so there’s a consistent push to explain differences in terms of random assortment than fitness maximization. Too bad, because natural selection matters now more than ever. [2]

[1] http://www.tdaxp.com/archive/2007/05/02/review-of-before-the-dawn-by-nicholas-wade.html
[2] http://www.tdaxp.com/archive/2007/12/14/what-if-evolution-works-15000-times-faster-than-we-imagined.html

Cavegirls were first blondes to have fun

Ultimately the question si to what extent ad hominem attacks are valid in social science critiques. I think it’s fair to describe our current conversation as one voice believing that if some findings of one published article are wrongly interpreted,the author’s entire body of work (including both findings and literature reviews) should be conclusively presumed to be flawed. Another view is that such a black list is foolish.

Andrew,

Thank you for your comment. I think we agree.

I’m unfamiliar with Kanazawa’s line of research. While I guessed his findings are true in my original post, certainly it’s possible to argue for ways in which human females are under less evolutionary pressure than human males (far more distant universal common ancestor, etc), so who knows. Ultimately we need more data, and I hope Kanazawa presents the rest of his findings.

However, as I read the PT piece, Kanazawa does not cite his own research in making claim 6. It seems that even ignoring the Kanazawa beauty article, he could have written #6 just the same.

I have not purchased his book, so I cannot comment on the claims made therein.

1. I agree with Daniel’s statement that Kanazawa’s statistics are so flawed that they do not prove what K. had claimed to prove. I also agree that Kanazawa’s claims could very well be true (and I think this is clear in my article). But I don’t think they would’ve been published as is, had the statistical flaws been realized. There are many many many possible conjectures to make, and Kanazawa’s claim in his article was that he had proven his results (to within reasonable confidence) statistically. So: “not proven,” not “false.”

2. On to the specifics: I agree about my comments (a) and (c). I think it should be possible to address (a) with additional data. There is no way to address (c); that was simply a mistake in the presentation of the results.

But on (b), I don’t suggest that K. do a Bonferroni correction. I agree that this is a possibility but I think that a simple regression coefficient (averaging the attractiveness ratings for all 3 waves of the study) would be the way to go. I brought up the Bonferroni correction in my article only because Kanazawa had picked such an odd comparison. Again, this concern could be addressed using new data (or, for that matter, using all 3 waves of the study). I think it’s likely the results won’t be statistically significant, but, again, that doesn’t make the claim false.

A power analysis suggests that if the sex ratio effects are in the range of 1% (which is perhaps a priori plausible), you’d need a huge sample size to find patterns. In this case, further analysis of Kanazawa’s existing data wouldn’t show much. I think it would be fair to say that the data are consistent with K.’s hypotheses, and the data are also consistent with many many other hypotheses.

Based on the evidence I’ve seen, I think it’s a little early to be writing a book called “Why beautiful people have more daughters” or presenting these conjectures as fact in Psychology Today. But I agree with Dan that my statistical criticisms shouldn’t be considered a reason to not study these things.

3. I like the Raftery article that you linked to. But Raftery and I have disagreements about statistical methods. Kanazawa was making mistakes with standard methods. This is a bit different. I don’t think Raftery would disagree with my criticisms of Kanazawa’s work at all. As I said in my blog entry, I suspect that if Kanazawa had collaborated with a statistician, that these errors wouldn’t have occurred. (But then the work, with its non-statistically-significant results, probably wouldn’t have appeared in J. Theor. Bio., and we might not be having this discussion at all.)

4. I think the hysterical (if that’s what it is) reaction on our blog was to Kanazawa’s presentation of unproved conjectures as proved. I don’t think it was a reaction to sociobiology etc. in general.