A university has found ‘robust evidence’ that bisexual men exist, amid challenges to the notion men can be attracted to both men and women.

East Anglian Daily Times: Scientists from Essex University have quashed claims bisexual men 'do not exist' Picture: UNIVERSITY OF ESSEXScientists from Essex University have quashed claims bisexual men 'do not exist' Picture: UNIVERSITY OF ESSEX (Image: Archant)

Scientists from the University of Essex alongside counterparts in the USA carried out the research to question a popular assumption that men are either straight or gay, rather than being aroused by both sexes.

It comes after Dr Gerulf Rieger, from the university’s department of psychology, admitted he had doubted the physical ability of men being attracted to both men and women.

Mr Rieger’s opinion was based on a previous study he had completed with Professor J. Michael Bailey of Northwestern University in 2005, which found no evidence of bisexual arousal in men. The small study led to a news article named “Straight, Gay, or Lying?” in the American press – which dismayed many in the bisexual and LGBTQ+ community.

The same team later confirmed the existence of bisexual arousal in men in 2011, but Essex University has since reanalysed the data of both studies – in addition to six more – to grant greater statistical power.

As part of the study, scientists reanalysed more than 400 men’s penile responses to erotic videos of men and women, and found clear evidence bisexual men are indeed aroused by both sexes.

The study found bisexual men were more aroused to erotic videos of women than gay men, and were also more aroused to similar videos of men than straight men. It also found bisexual men showed less difference in arousal to straight men and women.

Dr Rieger said: “It has always been clear that bisexual men exist in terms of self-identity and behaviour, but many, including myself, were sceptical about their ability to be sexually aroused to both men and women.

“Now, with this exceptional number of participants, we have clear proof of their bisexual arousal. This reshapes our entire understanding of male sexual orientation.”

Lead author Jeremy Jabbour, a PhD candidate at Northwestern, added: “Our results paint a powerful picture of male sexual orientation having gradients and nuance. Although I don’t think that bisexual men need research like this to validate or justify their lived experience to others, I’m hopeful that findings such as ours will continue to help the public see the many shades of gray that exist in human sexuality.”

The new study is published in the prestigious Proceedings of the National Academy of Sciences.