Noted: A 2013 study by the University of Wisconsin?s Waisman Center found hormones released when girls are abused could trigger early puberty. Rather than triggering the fight-or-flight hormone cortisol ? which is what happened when boys were abused ? researchers found that, after regular abuse, girls released oxytocin, a hormone we associate with post-coital and post-natal bonding. But too much cortisol can be just as damaging. Eventually, a body learns to become inured to the stressful situations that trigger its release.