Social interactions may be affected by epigenetics

The neural signaling molecule oxytocin, which influences how animals interact, is sometimes portrayed as a "love hormone," but it's not as simple as that. This should not be surprising, given that it is an evolutionarily ancient neuromodulator, one that impacts a wide range of emotion and social interactions—these are hardly simple things.

A more current, nuanced view of its effects holds that, rather than simply enhancing bonding, love, and trust, it serves to amplify people's social awareness. This can have a downside—like alcohol, it can amplify whatever feelings one already has toward someone else, whether they're positive or negative. It can also strengthen bonds only within a clique, to the exclusion of everyone at the other lunch tables.

While it's clear that oxytocin definitely has potent effects on emotion and social cognition, it's less clear how any of this happens. Individuals express varying levels of oxytocin, but these different levels have never been conclusively linked to any social abilities or disabilities—and that is not for lack of trying.