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Wild seals given 'love hormone' in experiment

Grey seals Image copyright Getty Images

Scientists have found that wild seals given a dose of oxytocin, nicknamed the love hormone, become more sociable and less aggressive.

A study of grey seal pups on the Isle of May found those given the hormone would also stay close to each other.

The University of St Andrews team said the effects of the hormone lasted for days despite the small doses given.

Oxytocin is known to forge emotional bonds between romantic partners, and mothers and newborn babies.

The experiment was conducted among wild newly-weaned grey seals in the Firth of Forth.

'Intense interest'

Adult seals were not considered suitable for the study because of the possibility that they were already socially connected, and their large size and aggressiveness.

Study leader Dr Kelly Robinson wrote in the journal Proceedings of the Royal Society B: "Seals given oxytocin spent significantly more time in close proximity to each other, confirming that oxytocin causes conspecifics (same species members) to seek others out and remain close to one another.

"Aggressive and investigative behaviours also significantly fell after oxytocin manipulations."

The scientists concluded: "Oxytocin manipulations have been subject to intense interest in the last decade due to the widespread occurrence of oxytocin in mammals, its far-reaching effects on behaviour including parental and social bonds and the potential to use the hormone to treat human psychological conditions.

"Despite this, no study has confirmed that behavioural changes that occur in laboratory manipulations also occur in natural environments, and many administer doses of oxytocin far exceeding endogenous levels.

"We show that manipulation studies are possible in wild populations, and that manipulations are most powerful after prior work to identify naturally existing hormone-behaviour relationships."

The research was conducted in a way that ensured no harm came to the seals, said the team.