Zak's research has identified hormone oxytocin -- believed to stimulate empathy, trust, generosity and all manner of social bonding -- as a vital ingredient in economic activity, encouraging us to connect with others in our community and society generally.
So how does this relate to your Facebook addiction? It's possible that your interactions online give you the same warm, cuddly feeling you get during face-to-face encounters with friends or family. If true, this has implications for companies with a social media presence, not to mention those of us using social media at work.
Penenberg took part in an experiment to determine tweeting's effects on his brain. Zak's team measured his oxytocin levels before and immediately after a 10-minute Twitter session. Six weeks later, it transpired his levels had spiked to those of a groom at a wedding, while his stress hormones dropped. In other words, Penenberg's brain interpreted tweeting as if it were a personal interaction -- like chatting with good friends over dinner.
Of course, Zak's findings have generated sceptics. But they also seem to have spawned a little sub-industry of social media experts talking in terms of "digital oxytocin", who rate trust-building as a metric on a par with margins. Their view is that companies such as Zappos, Carphone Warehouse and King of Shaves, which actively connect with customers online, will have the edge because they are building trust (raising our oxytocin levels) and making customers feel like close friends. Ain't love grand?