ABSTRACT
It is now widely appreciated that both oxytocin and vasopressin – either as neuroendocrine hormones or as neurotransmitters – modulate social behaviors. These nine amino acid peptides are released from their sites of production within the brain during social encounters to act on their receptors positioned on specific cells and circuits in the brain. Evidence for these findings comes from causal research designs in animal models as well as correlational studies in human research. Intranasal delivery of oxytocin has also become a popular research tool to identify a causal role for exogenous oxytocin on human behavior and brain activity. The majority of animal model and human research is performed in adults. This generates a nagging question for the developmental social neuroscientist – how do these neuropeptides contribute to the development of social behavior? This chapter will provide examples of the available evidence for oxytocin and vasopressin in social behavior from developing mammalian systems. The Developmental Uncanny Valley Hypothesis will be introduced as a research framework for generating specific testable mechanistic hypotheses for the roles of oxytocin and vasopressin in social behavior development. Finally, this chapter will highlight major knowledge gaps for the roles of oxytocin and vasopressin in the species-typical, experience-dependent development of social behavior.
