Dark side of the love hormone

2019-03-01 03:06:10

By Ed Yong FEW chemicals have as glowing a reputation as oxytocin. Billed as the “love hormone” or the “cuddle chemical”, it has been linked to almost every positive aspect of the human psyche. One whiff of it can make a person more trusting, empathetic, generous and cooperative. Such is its popular appeal that you can even buy it as a spray from dubious internet dealers. It is time to revise this rose-tinted view. A new wave of studies is showing that oxytocin is neither the cause of our better angels nor a panacea for the world’s social ills. In fact, its effects vary greatly depending on the person and the circumstances, and it can tweak our social interactions for worse as well as for better. The “love hormone”, it turns out, has a dark side, one that is only just starting to come to light. “It isn’t the wonder drug that makes everyone happy and social,” says Markus Heinrichs at the University of Freiburg, Germany, who pioneered work on oxytocin. We first became aware of the hormone’s social influence through animal studies. It helps to cement the bonds between prairie voles, which mate for life, and triggers the motherly behaviour that sheep show towards their newborn lambs. It is also released in humans during childbirth, strengthening the attachment between mother and baby. Its wider role in human behaviour only emerged in 2005 when, in a groundbreaking experiment, Heinrichs and colleagues asked volunteers to play a game in which they could invest money with an anonymous trustee,