Considerations of gender in regard to crime have been considered to be largely ignored and pushed aside in criminological and sociological study, until recent years, to the extent of female deviance having been marginalized. In the past fifty years of sociological research into crime and deviance, sex differences were understood and quite often mentioned within works, such as Merton's theory of anomie; however, they were not critically discussed, and often any mention of female delinquency was only as comparative to males, to explain male behaviors, or through defining the girl as taking on the role of a boy, namely, conducting their behavior and appearance as that of a tomboy and by rejecting the female gender role, adopting stereotypical masculine traits.