Acute effects of steroid hormones and neuropeptides on human social-emotional behavior: a review of single administration studies.

Steroids and peptides mediate a diverse array of animal social behaviors. Human research is restricted by technical-ethical limitations, and models of the neuroendocrine regulation of social-emotional behavior are therefore mainly limited to non-human species, often under the assumption that human social-emotional behavior is emancipated from hormonal control. Development of acute hormone administration procedures in human research, together with the advent of novel non-invasive neuroimaging techniques, have opened up opportunities to systematically study the neuroendocrinology of human social-emotional behavior. Here, we review all placebo-controlled single hormone administration studies addressing human social-emotional behavior, involving the steroids testosterone and estradiol, and the peptides oxytocin and vasopressin. These studies demonstrate substantial hormonal control over human social-emotional behavior and give insights into the underlying neural mechanisms. Finally, we propose a theoretical model that synthesizes detailed knowledge of the neuroendocrinology of social-emotional behavior in animals with the recently gained data from humans described in our review.