ChapTer 3 Development Over the Life Span 97referred to as he or she. Some feel uncomfort-
able in their sex of rearing and wish to be consid-
ered a member of the other sex. Transsexuals are
usually not intersexed, yet likewise feel that they
are male in a female body or vice versa; their
gender identity is at odds with their anatomical
sex or appearance. Many transsexuals try to make
a full transition to the other sex through surgery
or hormones. Intersexed and transsexual people
have been found in virtually all cultures through-
out history (Denny, 1998; Roughgarden, 2004).
influences on Gender identity
and Development Lo 3.12
To understand the typical course of gender devel-
opment, as well as the variations, developmental
psychologists study the interacting influences of
biology, cognition, and learning on gender iden-
tity and gender typing.
Watch the Video The Basics: Sex and Gender
Differences at MyPsychLabBiological influences. Starting in the pre-
school years, boys and girls congregate primarily
with other children of their sex, and most prefer
the toys and games of their own sex. They will
play together if required to, but given a choice,
they usually choose to play with same-sex friends.
The kind of play that young boys and girls enjoy
also differs, on average. Little boys, like young
males in all primate species, are more likely than
females to go in for physical roughhousing, risk
taking, and aggressive displays. These sex differ-
ences occur all over the world, almost regardless
of whether adults encourage boys and girls to play
Throughout history and across cultures, some people have broken out of conventional gender categories. Some women
have lived as men, as did the eighteenth-century pirates Ann Bonny and Mary Read (left). Some men have lived as
women: The Muxes (pronounced moo-shays) of southern Mexico are males who consider themselves female, live as
females, and are a socially accepted category (center). Some individuals do not wish to identify as traditionally male
or female. Thomas Beatie (right) was born a genetic female and later had a sex-change operation. Because he had a
womb, he was able to become the world’s first “pregnant man.”
together or separate them (Lytton & Romney,
1991; Maccoby, 1998, 2002). Many parents lament
that although they try to give their children the
same toys, it makes no difference; their sons want
trucks and guns and their daughters want dolls.
Biological scientists believe that these play
and toy preferences have a basis in prenatal hor-
mones, particularly the presence or absence of
prenatal androgens (masculinizing hormones).
Girls who were exposed to higher-than-normal
prenatal androgens in the womb are later more
likely than nonexposed girls to prefer “boys’
toys” such as cars and fire engines, and they are
also more physically aggressive than other girls
(Berenbaum & Bailey, 2003). A study of more than
200 healthy children in the general population
also found a relationship between fetal testos-
terone and play styles. (Testosterone is produced
in fetuses of both sexes, although it is higher on
average in males.) The higher the levels of fetal
testosterone, as measured in the amniotic fluid
of the children’s mothers during pregnancy, the
higher the children’s later scores on a measure of
male-typical play (Auyeung et al., 2009). In studies
of rhesus monkeys, who of course are not influ-
enced by their parents’ possible gender biases,
male monkeys, like human boys, consistently and
strongly prefer to play with wheeled toys rather
than cuddly plush toys, whereas female monkeys,
like human girls, are more varied in their toy pref-
erences (Hassett, Siebert, & Wallen, 2008).
What about the stories in the news of very
young boys who not only want to play with girls’
toys but want to be girls? Or little girls who want
to be boys? In 2013, the parents of one such child
sued the school system to allow their son—whom
they now consider their daughter—for the right to