The ‘Love hormone’ oxytocin that helps the mother-baby bond also fosters kindness among irritable monkeys.
Administering the hormone nasally, a Duke University research team has shown that it can make rhesus macaques pay more attention to each other and make choices that give another monkey a squirt of fruit juice, even when they don’t get one themselves.
Two macaques were seated next to each other and trained to select symbols from a screen that represented giving a rewarding squirt of juice to one’s self, giving juice to the neighbour, or not handing out any juice at all.
In repeated trials, they were faced with a choice between just two of these options at a time: reward to self vs. no reward; reward to self vs. reward to other; and reward to other vs. no reward, the journal Proceedings of the National Academy of Sciences reports.
“The inhaled oxytocin enhanced ‘prosocial’ choices by the monkeys, perhaps by making them pay more attention to the other individual,” said neuroscientist Michael Platt, who headed the study and is director of the Duke Institute for Brain Sciences, according to a Duke statement.
“If that’s true, it’s really cool, because it suggests that oxytocin breaks down normal social barriers,” added Platt. Earlier work by Platt’s group had shown that macaques would rather give a reward to another monkey when the alternative is no reward for anyone, a concept they call “vicarious reinforcement.”
The hormone is currently being evaluated as a therapy for autism, schizophrenia and other disorders that are marked by an apparent lack of interest or caring about others, Platt said.
It seems to give patients increased trust and better social skills, but not much is known about how that process works, or whether the effects would be consistent over the long term.