Dear Sir,

In his recent Commentary[1], Ben Barres concedes that his testosterone treatment caused significant behavioral changes, including a measurable increase in visuospatial ability. Though he claims that such differences are not "at all relevant to the abilities necessary to be successful in a chosen academic career," an examination of the literature reveals that the ability to rotate objects in three dimensions is demonstrably important in engineering and the physical sciences[2,3].

Barres's article is rife with such contradictions. While Barres argues that more female representation would "[lessen] the hostile working environment" in the sciences, he also claims that "there is no scientific support ... for the contention that women are innately less competitive." He states that merit is a function of quality rather than quantity--eliding the fact that eminent scientists achieve both[4]--yet he has publicly expressed disappointment over losing a fellowship to a competitor with one-sixth his publication rate[6]. Barres disparages Peter Lawrence for stating that "there is good psychological evidence that aggression ...[is] on average [a] male characteristic"[7], but Barres himself claims that "women...tend to be less confident" when it comes time to "exert a presence at meetings." Perhaps most dramatically, within the span of two paragraphs, Barres moves from agreeing that "all ideas are fair game" to characterizing the defense of certain ideas as "verbal violence"--as "free speech that is not fully protected"!

More serious than these internal contradictions are the many empirical shortcomings in Barres's article. A partial account:

1) The claim that "one-third of the winners of the elite Putnam Math Competition last year were women" is false. In 2005, one woman (Alison B. Miller) was among the 24 winners, while in 2004 there were 4 among the 26 winners (Miller, Ana Caraiani, Olena Bormashenko, and Inna Zakharevich).

2) The paper[8] providing the data presented in Barres's Figure 1 hardly qualifies as a representative citation of the now-massive literature on sex differences in cognitive abilities, which documents among other differences a large male advantage on tests of spatial-visualization[8-13] and greater male variance in test scores overall[14-19]. Moreover, the effects reported by Leahy and Guo are consistent with this literature despite their atypically small size. From the abstract: "Despite relatively equal starting points in elementary school, and relatively equal slopes, we find that boys have a faster rate of acceleration. By the 12th grade, this results in a slight gender difference, which is most pronounced in geometry." From the body of the paper: "[W]e find that the gender difference in math score is the greatest among high-scoring students, but in this case it always favors males."

3) Barres cites a study[20] purporting to show sex discrimination during the selection of 24 postdoctoral fellows in 1997. However, a more recent analysis[21] of a much larger sample (the EMBO Long Term Fellowship) concludes: "One could claim that women needed a greater number of publications in order to be successful, but the data equally illustrate a need for men to have publications with a higher impact factor. Crass discrimination against women therefore does not take place."

4) Barres states that "minorities are at a profound disadvantage in competitive selection unless the processes are properly designed" and offers the tiny sample of the NIH Pioneer Award as definitive support. Yet even a cursory examination of the recipients of prestigious pre- and post-doctoral fellowships such as NDSEG, NSF, Hertz, and Damon Runyan shows a significant overrepresentation of Asian Americans among the winners. The same pattern holds for junior faculty in science and engineering at elite institutions across the United States, as well as for HHMI Investigators and recipients of the NSF Career Award. This is not just a matter of imprecision on the part of Barres. Although he accuses the Academy of indiscriminate anti-minority bias, the differential outcomes of disparate groups indicate that bias of any kind must be very discriminating indeed.

Finally, in addition to noting the contradictions and empirical inaccuracies in Barres's article, it is important to point out the omissions. Absent is any mention of sex differences in embryonic neural gene expression[22], of sex-mediated variation in risk for a host of neurological disorders[23], of sex differences in the neuroanatomical substrate of general intelligence[24], of male v. female patterns of brain activity during mathematical tasks[25], or indeed of any of what Susan Forger refers to as the "100 sex differences between male and female brains described so far"[26]. Tellingly, also absent is any acknowledgement that women show reproducibly superior performance on tests of memory and perceptual speed[9,12], obtain higher Varimax-rotated principal component scores on the reading portion of the Program for International Student Assessment in all 29 participating countries[27], and in fact are overrepresented in some academic disciplines[28]. Barres's refusal to substantively engage with the mountain of evidence contrary to his position serves the same purpose as the numerous inflammatory anecdotes in his article; namely, by omitting the evidence for male advantage on some tasks and female advantage on others, Barres seeks to equate dispassionate inquiry into sex differences with impassioned proclamations of inferiority.

Godless Capitalist
------- University

Darth Quixote
------- University

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