Whilst the ‘love hormone’ oxytocin has been well documented to promote bonding and trust between people, a new study suggests that it may also play a role in the ‘in-group/out-group’ mentality that reaches it’s sharpest focus on the battle field. Researchers at the University of Amsterdam have found that volunteers given oxytocin nasal spray bonded and became much more protective of people seen as belonging to their own group, but grew far more hostile and aggressive to those perceived as outsiders.
Dr Carsten De Dreu, of the University of Amsterdam, said that the phenomenon was known as “parochial altruism” or “tend and defend”.
This meant that boosted levels of oxytocin produced “in-group love” and “out-group aggression”, he said.
Dr De Dreu, who published the findings in Science, said: “Oxytocin is a double edged sword. It makes you kinder to your group but more aggressive to those outside.”