A NASAL spray made of the hormone vasopressin improves men’s ability to recognise the emotions of both happy and angry – but not neutral – faces.

Related “cuddle chemical” oxytocin improves bonding. So does vasopressin, but it also drives less cosy aspects of social behaviour, such as aggression.

So Adam Guastella at the University of Sydney in Australia compared the ability of 24 men given the spray to recognise neutral, angry and happy faces with peers given a placebo spray (Biological Psychiatry, DOI: 10.1016/j.biopsych.2010.03.014).

“There may be an application in people with inadequate recognition of social cues,” Guastella says.