Oxytocin
It has been shown that oxytocin differentially affects males and females. Females who are administered oxytocin are overall faster in responding to socially relevant stimuli than males who received oxytocin. Additionally, after the administration of oxytocin, females show increased amygdala activity in response to threatening scenes; however, males do not show increased amygdala activation. This phenomenon can be explained by looking at the role of gonadal hormones, specifically estrogen, which modulate the enhanced threat processing seen in females. Estrogen has been shown to stimulate the release of oxytocin from the hypothalamus and promote receptor binding in the amygdala.
Homewrecker
Scientific American, tongue-in-cheek, referred to oxytocin as a homewrecker. The hormone normally triggers a nesting instinct, which makes it a "home builder", not a homewrecker. But with chronic exposure in prairie voles, a study instead showed a breakdown of the normal nesting instincts: The animals avoided pair bonding and child nurturing. This raises questions about the growing practice of using oxytocin to treat behavior disorders such as autism.