identical twins

Researchers Are Studying the Science of Sexuality With Identical Twins, One Gay and One Straight

In a controversial new study, identical twins with differing sexual orientations are being studied to explore the science of sexuality.

Rosie Ablewhite and Sarah Nunn are genetically identical and grew up together. But the 29-year-olds are a mystery to sexuality researchers because Sarah is straight but Rosie is gay.

“Any boyfriend instantly felt more at home with Rosie,” Sarah told the Times.

“She liked football, talked about boy things, played video games. They’d be like, ‘Sarah, you’re really boring. I’m going to go and play with Rosie.’

“I’d get jealous that they liked her better,” Sarah said.

But, when any boy tried to make a romantic move on Rosie, she would always turn them down.

The twins are now being studied by scientists to find out how genes and the environment we live in affect sexuality.

Gerulf Rieger and Tuesday Watts, from the University of Essex, conducted a study where the researchers showed people childhood photos of 56 pairs of twins with “discordant sexual orientations.”

Participants were asked whether they could tell from the twin’s clothing and mannerisms if they ended up being gay. Some have criticized the work, suggesting that it reinforces gender stereotypes. But the study suggests that markers of sexual orientation may manifest before puberty.

“What we can do is rule out a few things now,” said Rieger. “A lot of people jump to the conclusion it must be genetics.”

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“This shows there is something early on, in the early environment, that has nothing to do with genes but can still have a tremendous effect on sexual orientation.”

Rieger adds that sexual orientation could be determined before birth, explaining why identical twins can have different sexual orientations.

“Prenatal hormones are the number one candidate,” he says. “Our theory is that even though twins are identical, what happens in the womb can be quite different. They can have different nutrition, different levels of hormones.”

Rieger knows his work is controversial, but insists that to him it just a way of assessing behaviors.

“It doesn’t matter to me if it’s controversial,” he added. “It’s very dangerous to start going down the route of thinking that way.”