Being nice is associated with all kinds of benefits. Humans are wired to enjoy the “warm glow” of feeling like we’ve improved someone else’s well-being, Simon-Thomas says—doing so triggers the brain pathways that signal pleasure. Plus, “having more social interactions that are safe and benevolent is a way to feel like you belong,” she says. “If we can walk around our communities and have friendly interactions, we feel like we belong in that community, as opposed to walking around and feeling sharp or edgy or grumpy—in which case we're more vigilant and guarded.”