Do Mums and Dads make Boys Gay and Girls Lesbian (respectively)?

According to a new piece of scientific research our sexual orientation can be decided in the womb by rogue “epi-marks” that we receive from our opposite sex parent.

Challenging the current conflicting orthodoxies that we are either a product of our environments or we have inherited the “gay gene” in our DNA, researchers William Rice, a professor at the University of California, Santa Barbara, and Urban Friberg, a professor at Uppsala University in Sweden, believe that homosexuality can be explained by the presence of epi-marks — temporary switches that control how our genes are expressed during gestation and after we’re born.

Epi-marks are inherited and attach themselves to genes. If genes are the ‘what’ defining our characteristics, epi-marks are the ‘how’ defining how the characteristics manifest themselves. This can include controlling the levels of testosterone in the developing foetus. Generally the epi-marks are newly created in each generation but sometimes they cross-over from mother to son or father to daughter – causing homosexuality.

The research is published in The Quarterly Review of Biology and has already raised eye-brows, partly because of its reliance on mathematical models but moreover because it reawakens dark images of medical explanations of sexual orientation and implies that we are not ‘normal’. The researchers however assert that the whole process is a part of Darwin’s natural selection rather than any kind of aberration.

To read a summary of the research go here.

To read the full document go here.