Oxytocin and sex differences in behavior

Oxytocin is an evolutionarily ancient neuropeptide that is implicated in the neural modulation of behavior in vertebrates. While this system is well known for its species-specific effects, there is a lack of consensus regarding oxytocin's sex-specific effects - due in part to shortcomings in the way that studies have traditionally been designed. Sex differences in the neuroanatomy of the oxytocin system are not abundant and are generally not predictive of sex differences in behavior. Rather, it is possible that the differential evolution of these systems in males and females has resulted in sex differences in the sensitivity to oxytocin as well as sex differences in the function of the neural circuitry important for behavioral displays. This hypothesis is supported by work which suggests that sex differences in behavior are likely due to sex-specific patterns of activity between brain regions that have been implicated in the regulation of social behavior. It is also important to consider how oxytocin's sex-specific behavioral effects are shaped by social context, species evolution, and an animal's behavioral ecology.