Oxytocin and vasopressin have effects that are the polar opposite of T’s. They decrease excitability in the amygdala, making rodents less aggressive and people calmer. Boost your oxytocin levels experimentally, and you’re more likely to be charitable and trusting in a competitive game. And showing how this is the endocrinology of sociality, you wouldn’t have the response to oxytocin if you thought you were playing against a computer.[15]
