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.
Endocrinology of parenting
Oxytocin in human females is associated with the level of physical affection and bonding. Feldman (2010) found that mothers who displayed “high affectionate contact” had increased oxytocin levels post interaction, but not mothers who displayed “low affectionate contact.” Oxytocin is believed to provide a feedback loop, meaning that maternal-infant contact increases oxytocin and oxytocin increases maternal behavior and facilitates bonding. In one study oxytocin also played a role on mother reported attachment to her fetus.