Sexual harassment from males prevents female bonding, says study

The extent to which sexual harassment from males can damage relationships between females is revealed in a new study.

Led by the Centre for Research in Animal Behaviour at the University of Exeter and published in Proceedings of the Royal Society B, the research uncovers the effect of sexual harassment on the ability of female fish to form social bonds with each other.

The study focused on guppies, a popular aquarium fish, in which scientists have previously observed a very high level of sexual harassment from males towards females. The researchers found that male harassment not only breaks down female social structures but also affects females' ability to recognise one another.

The research provides the first insight into the effect of male sexual harassment on female social networks and social recognition. The findings could have relevance to other species.

Lead author Dr Safi Darden of the University of Exeter explains "Sexual harassment is a burden that females of many species ranging from insects to primates suffer and the results of our work suggest that this harassment may limit the opportunities for females to form social bonds across a range of species"

The research team worked with a population of wild guppies in Trinidad, isolating the females and introducing males to change the sex ratio and examining the effect of males on female social behaviour. They carried out a number of experiments on each group to test the females' ability to recognise their peers and form bonds with other members of the group.

The study showed that, after experiencing a high level of sexual harassment, females were less able to recognise the other females in the group. They were also more likely to form bonds with new females, introduced from outside their network.

Co-author Dr Darren Croft of the University of Exeter said "This is an extremely interesting result as it appears that females that experience sexual harassment actually prefer to avoid other females with whom they associate the negative experience."

Those females that were grouped without males were better able to recognise one another and also showed a preference for females from within, rather than outside, the group.

Dr Safi Darden adds: "The health and well-being of an individual is dependent, in part, on having strong social bonds with others and females that have weakened social bonds may be less likely to survive in the wild. This makes the effect of male harassment quite significant, but it is an area that has not previously been studied."

The researchers do not know exactly why sexual harassment from males has such a marked effect on female social interaction. However, it is possible that the sheer amount of time spent by females dealing with unwanted male attention prevents them from forming relationships with other females. They believe females from groups with more males may have bonded with females from outside in order to try to establish themselves in a more favourable environment.