The facial width-to-height ratio (face ratio), is a sexually dimorphic metric associated with actual aggression in men and with
observers’ judgements of aggression in male faces. Here, we sought to determine if observers’ judgements of aggression
were associated with the face ratio in female faces. In three studies, participants rated photographs of female and male
faces on aggression, femininity, masculinity, attractiveness, and nurturing. In Studies 1 and 2, for female and male faces,
judgements of aggression were associated with the face ratio even when other cues in the face related to masculinity were
controlled statistically. Nevertheless, correlations between the face ratio and judgements of aggression were smaller for
female than for male faces (F1,36 = 7.43, p = 0.01). In Study 1, there was no significant relationship between judgements of
femininity and of aggression in female faces. In Study 2, the association between judgements of masculinity and aggression
was weaker in female faces than for male faces in Study 1. The weaker association in female faces may be because
aggression and masculinity are stereotypically male traits. Thus, in Study 3, observers rated faces on nurturing (a
stereotypically female trait) and on femininity. Judgements of nurturing were associated with femininity (positively) and
masculinity (negatively) ratings in both female and male faces. In summary, the perception of aggression differs in female
versus male faces. The sex difference was not simply because aggression is a gendered construct; the relationships between
masculinity/femininity and nurturing were similar for male and female faces even though nurturing is also a gendered
construct. Masculinity and femininity ratings are not associated with aggression ratings nor with the face ratio for female
faces. In contrast, all four variables are highly inter-correlated in male faces, likely because these cues in male faces serve as
‘‘honest signals’’