32 CHAPTER ONE
area in women — 10 percent larger straight gyrus on average compared with
in men. Further, the size of the straight gyrus correlated positively with
scores on a social intelligence test — the greater the volume of the straight
gyrus, the better the score. None of the methods they used can give any
evidence of origins or causality, but Wood, Heitmiller et al. suspect that the
differences they measured are caused by “early in utero hormonal exposure
interacting with expression of specific genes,” which “facilitates the develop-
ment of elaborate social cognition and behavior systems” (540). While the
researchers make room for epigenetics or gene expression, they nonetheless
use evolutionary theory to explain social intelligence as an inherently female
trait, which evolved for the reproductive goals of “rearing young” (540).
Feminists have called into question this use of evolutionary theory, chal-
lenged the reliability and validity of such findings, and offered extensive
methodological critiques (Fausto- Sterling et al. 2000; Fine 2010; Fine et al.
2013; Jordan- Young 2010; Jordan- Young and Rumiati 2012; Kaiser in press,
2016; Rippon et al. 2014; Schmitz and Hoeppner 2014).^19 In addition, they
have demanded reconciliation of the theories of innate difference with evi-
dence of the brain’s plasticity, arguing that where genuine differences are
found, there is no reason to assume they are innate. Instead, if the brain and
the environment are dynamically integrated, then an environment that en-
courages different opportunities, activities, social scripts, attitudes, and per-
sonal characteristics for males and females may account for differences in
behavior, as well as measures of their brain morphology. As Jordan- Young
and Rumiati (2012) put it, “given pervasive gender socialization and wide-
spread gender segregation in occupation and family responsibilities, it is
utterly predictable that we would observe group- level differences between
men and women in various cognitive functions. It is frankly somewhat sur-
prising to us that we do not see greater differences and less overlap, and also
would not be especially surprising to see more structural differences than
there seem to be” (312). Thus, in the example of the straight gyrus, females
could get proportionally more volume there as they grow up, as they in-
creasingly use it in gendered tasks and styles of thought that demand more
social sensitivity.^20 Not evolutionary dictates but rather the more intensive
emotion work expected of girls and women would have an effect on areas
of the brain that purportedly subtend this cognitive and affective behavior.
By contrast, males could see less volume there because of pruning or cor-