122 Chapter 4early in life. In a study of 17-month-olds,
parents reported that boys were more likely
than girls to kick, hit, and bite (Baillargeon
et al., 2007). Boys were also 2.5 times more
likely than girls to be classified as highly ag-
gressive. The sex difference in aggression
remained the same when these children
were followed for 1 year.
Like the other domains in which
women and men are compared, aggression
is influenced by a variety of situational vari-
ables. One important situational factor is
provocation, which may release women from
the constraints the female gender role places
on aggressive behavior. The Bettencourt
and Miller (1996) meta-analysis showed
that provocation led to greater aggression
than nonprovocation, and that provocation
altered the size of the sex difference in ag-
gression. The sex difference was smaller un-
der provocation conditions (d=+.17) than
under neutral conditions (d=+.33). In ad-
dition, a judge’s rating of the intensity of a
provocation was negatively correlated with
sex differences in aggression; in other words,
the stronger the provocation, the smaller the
sex difference.
Another situational variable that has
been investigated is the emotional arousal
generated by the situation. Because males
may be more easily aroused than females and
less able to regulate their emotions, Knight
and colleagues (2002) predicted that sex dif-
ferences in aggression would be minimal in
situations of no/low or very high emotional
arousal and maximal in situations of medium
emotional arousal. As shown in Figure 4.11,
at very low levels of arousal, one would ex-
pect sex differences to be small because both
men and women can control their behavior.
At very high levels of arousal, sex differences
also would be small because emotion regula-
tion is disrupted in both males and females.Turn Violent and How We Can Save Themby
James Garbarino (1999),The Minds of Boys:
Saving Our Sons from Falling Behind in School
and Lifeby Michael Gurian and Kathy Stevens
(2007), andThe Purpose of Boys: Helping Our
Sons Find Meaning, Significance, and Direction
in Their Livesby Michael Gurian (2009).Sex of Perpetrator. Observational stud-
ies of children confirm sex differences in
aggression at an early age, and these differ-
ences generalize across cultures (Munroe
et al., 2000). Boys are more likely than girls
to use weapons and are more likely than girls
to carry a weapon to school (Cao, Zhang, &
He, 2008). A national survey of high school
students showed that 27% of boys compared
to 7% of girls had carried a weapon, such as
a gun or a knife, in the past 30 days (Cen-
ters for Disease Control and Prevention,
2010a). These figures were roughly similar
for White, Black, and Hispanic students, al-
though White males were most likely to have
carried any weapon (29%) and Black male
students were most likely to have carried a
gun (13%). Adolescent boys report a greater
acceptance of aggression compared to girls
and are more likely to use aggression to solve
problems (Garaigordobil et al., 2009).
A meta-analytic review of sex com-
parisons showed that men were more ag-
gressive than women (Bettencourt & Miller,
1996). Sex differences in verbal aggression
were less consistent than sex differences in
physical aggression. There were no sex dif-
ferences in verbal aggression in the field
(d=+.03) and only a small sex difference
in the laboratory (d=+.13; Bettencourt &
Miller, 1996). When more indirect forms
of aggression, such as relational aggression,
are examined (as discussed in Chapter 7),
sex differences may disappear. Sex differ-
ences in aggression also seem to appearM04_HELG0185_04_SE_C04.indd 122 6/21/11 8:02 AM