On the mood front, oxytocin is known to increase levels of feel-good hormones such as serotonin and dopamine, which may be why it has calming effects. "It reduces depression and anxiety, and it may have an effect on attentional disorders," Field says. In fact, a 2010 study from Ohio State University found that when socially-housed animals were treated with a pharmacological agent that inhibited oxytocin signaling, they exhibited an increase in depressive-like behavior.

　　The take-home message: Just because we're in the midst of cold and flu season, there's no reason to keep your distance from people you care about. "Like diet and exercise, you need a steady daily dose of hugging," Field says. But the quality of the hugging counts, too. "If you get a flimsy hug, that's not going to do it," Field says. "You need a firm hug" to stimulate oxytocin release.

　　Getting a firm, feel-good hug before going into a stressful situation (such as giving a presentation at work orgoing for a worrisome medical examination) could even help you stay calm, cool and collected during the event because your oxytocin levels are likely to stay elevated. A 2012 study from The Netherlands found that when oxytocin is administered nasally, saliva levels of the hormone stay high for more than two hours.

　　Of course, you won't actually know if your oxytocin level shoots up with hugging, but don't sweat it. The hug itself is likely to make you feel supported and cared about. "I suggest not worrying too much about the oxytocin portion, since what really matters is how these interactions impact emotional well-being," Norman says. In this case, feeling is as good as believing in the power of oxytocin.