Vasopressin acting on the vasopressin receptor 1A may regulate pair bonding behavior.

“And turns out that levels of vasopressin and/or vasopressin receptor dictate whether or not they're monogamous or not. And there's actually some interesting evidence in humans. When people report their behavior, assuming they're reporting accurately, that vasopressin and vasopressin levels can relate to monogamy or non-monogamy in humans as well.”

“So the most likely other candidate it's going to be vaseesscent because the same folks who had sort of identified oxytocin as being sort of really important for pair bonding. It also suggested vasopressin might play sort of you know a similar role and vasopressin like oxytocin is a neuropeptide hormone. So it's about nine amino acids. Um, so it's a short peptide um and it binds a different receptor vasopressin receptor 1A that regulates pair bonding behavior.”