Dr René Hurlemann’s initial research, which was published in November, revealed for the first time that there seemed to be a natural mechanism in people which sees intimacy triggering higher oxytocin levels.
The theory comes from a two-year experiment in which a group of 20 men were given a nasal spray containing the hormone. They were then shown pictures of other women and one of their partner.
His experiment measured the men's brain activity after being given the spray. The majority showed considerably more activity in the reward centre of their brain when looking at a picture of their partner, suggesting they found them more attractive. A placebo spray provoked less of a reaction.
“A lot of oxytocin is produced at the beginning of a relationship,” said Hurlemann. “This is because there tends to be more sex then."
“You see couples who have been together for a long time touching and kissing each other often,” he said, explaining that this may be the trick to staying, if oxytocin does indeed live up to its “cuddle hormone” name and its release triggered by physical contact.
Yet for Hurlemann's team at the University of Bonn, one thing remains unclear – whether a relationship breaking down, or cheating, is due to a “natural half life of oxytocin or a drop in the hormone caused by reduced physical contact.”
“This will be very difficult to figure out,” he told The Local on Friday, adding that his team had moved onto what he called “moral decision making tests.”
These saw men and women taking the spray and being put in a room with an attractive member of the opposite sex.
Although the final results are not published, Hurlemann said that women had so far proved to be worse than men at resisting approaching the bait.
Oxytocin is not just connected to sex though, current research is underway at the moment as to the effect it can have on people with autism.
“Basically what these experiments seem to be showing is that oxytocin could help those with social function disorders like autism, borderline personality disorder and schizophrenia,” said Hurlemann.
This was the first time that humans had been tested on – until now all evidence for the “cuddle hormone” had come from experiments on voles, said Hurlemann.