Swimming in hormones strengthens group

DidUhear – HAMILTON – McMaster University researchers have found that the hormone responsible for making humans fall in love has a similar effect on some fish, ScienceDaily reports.

Department of Psychology, Neuroscience and Behaviour researchers examined why the chichlid fish in Lake Tanganyika in Africa have shorter fights and are more likely than other fish species to get along better in supportive communities.

“We know how (oxytocin) affects humans,” said lead researcher Adam Reddon, whose study is published in the latest Animal Behaviour journal.

“It is related to love, monogamy, even risky behaviour, but much less is known about its effects on fish.”

When researchers gave fish their version of the hormone or just a saline solution, fish that received the hormone were more aggressive towards large opponents and in situations where their own group was involved, they were less aggressive.

“The hormone increases responsiveness to social information and may act as an important social glue,” said Reddon. “It ensures the fish handle conflict well and remain a cohesive group because they will have shorter, less costly fights.”