Sex-Related Comparisons: Theory 137spatial abilities in boys. There is also evidence
that CAH females are similar to nonaffected
males in terms of brain structure. In a study of
brain activation in response to facial emotions,
amygdala activation in CAH females was
stronger than that observed among non-CAH
females and similar to that observed among
males (Ernst et al., 2007).
Is there any evidence that hormones
are related to social behavior? Again, we can
turn to the studies on CAH. In a study that
compared 3- to 11-year-old CAH girls and
boys to their unaffected siblings, CAH girls
were more active and aggressive than non-
CAH girls, similar to levels of non-CAH boys
(Pasterski et al., 2007). There were no differ-
ences in activity or aggression between CAH
and non-CAH boys. Similar findings have
been shown with respect to play behavior.
CAH girls are less likely to play with female
toys and more likely to play with male toys,
whereas play behavior in boys is unaffected
by CAH (Hines, Brook, & Conway, 2004).
Researchers also have investigated
whether exposure to prenatal androgens is
linked to sexual orientation or gender iden-
tity problems. There may be a link between
CAH and homosexuality or bisexuality in
women (Hines et al., 2004). However, the
size of this effect is small, meaning a major-
ity of CAH women are heterosexual. In ad-
dition, it is the degree of prenatal exposure
to androgens that seems to be related to a
greater likelihood of homosexuality or bi-
sexuality in CAH women (Meyer-Bahlburg
et al., 2008). CAH does not seem to be asso-
ciated with gender identity problems. In an
examination of 250 individuals with CAH
reared as females, only 13 reported any gen-
der identity problems, 4 of whom wished to
be male (Dessens, Slijper, & Drop, 2005).
There are three potential explana-
tions for the link of CAH to spatial skills,(e.g., enlarged clitoris); boys do not have any
adverse effects on their genitals but may suffer
other ill effects from an excess of androgen.
What is the consequence of exposure to
an excess of androgens in utero? In terms of
cognition, a meta-analytic review of the litera-
ture showed that girls with CAH have superior
spatial skills compared to girls without CAH
(Puts et al., 2008). The link of testosterone
to spatial skills is not a simple one, however,
because boys with CAH had inferior spatial
skills compared to boys without CAH (Puts
et al., 2008). Puts and colleagues suggested a
curvilinear relation between androgens and
spatial abilities, as shown in Figure 5.1, which
would explain why exposure to androgens in-
creases spatial abilities in girls but decreasesGirlsLow High
AndrogensSpatial SkillsBoysCAH GirlsCAH BoysFIGURE 5.1 Hypothetical relation of andro-
gen exposure to the development of spatial skills.
Both low and high levels of exposure to andro-
gens are related to lower levels of spatial skills.
Because girls have lower levels of androgens than
boys, increased exposure to androgens in utero
(CAH) increases their spatial ability. By contrast,
additional exposure to androgens among boys
leads to decreased spatial ability. Thus, very low
levels of androgens (non-CAH girls) and very
high levels of androgens (CAH-boys) are associ-
ated with lower levels of spatial ability.
Source: Adapted from Puts et al. (2008).M05_HELG0185_04_SE_C05.indd 137 6/21/11 8:03 AM