Men in same-sex relationships are significantly less likely to have a degree in a STEM subject than those in different-sex couples, according to a new study.

Researchers, including from the University of Exeter Business School, believe they have identified a new science, technology, engineering and maths (STEM) gap.

Their finding follows previous studies that have established how race and gender influence student choice on whether to study STEM subjects at degree level.

The peer-reviewed study identified 142,641 men and women in same-sex couples and 10,809,885 men and women in different-sex couples.

It used the American Community Surveys from 2009 to 2018, along with additional data from the National Health Interview surveys between 2013 and 2018, including information on undergraduate degrees taken and occupation.

A man in a same-sex couple was 12% less likely to have a STEM degree than men in different-sex couples.

No such gap was discovered for women in same-sex couples studying STEM subjects and women in different-sex couples, though women were found to be underrepresented in such fields overall.

Dr Dario Sansone, lecturer in economics at the University of Exeter Business School, said: “These patterns are highly suggestive that the mechanisms underlying the very large gender gap in STEM fields such as heteropatriarchy, implicit and explicit bias, sexual harassment, unequal access to funding and fewer speaking invitations are related to the factors driving the gap in STEM fields between gay men and heterosexual men.

“For example, perceptions that gay men are relatively feminine and that lesbian women are relatively masculine may contribute in part to the underrepresentation of gay men compared to heterosexual men in STEM and the lack of differential representation of lesbians compared to heterosexual women in STEM.”

The study found that the STEM sexual orientation gap for men was larger than the gap between white and black men, which was 4%.

However the STEM gender gap was 21%.

The researchers hope their findings will spark a new focus on sexual orientation when considering the status of minorities in STEM fields.

Dr Sansone said that addressing the gap would create a level playing field, as well as potentially improving group decision making, company performance and the quality of scientific work.

The study, entitled Turing’s children: Representation of sexual minorities in STEM, is published in the journal Plos One.