Australasian Science: Australia's authority on science since 1938

Born This Way

By Guy Nolch

A study reporting a weak association between two genes and homosexuality could have powerful consequences.

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On 7 December 2017 the Australian Parliament passed a historic bill legalising gay marriage. The process followed a nationwide postal vote in which 61.6% of the 12.7 million Australians who voted were in favour of same-sex marriage.

The Yes campaign had argued that marriage was a basic civil right that should be open to all regardless of their sexuality. The No campaign had appealed to those who believed that homosexuality was “unnatural” and should not be sanctioned in legislation.

Humans are complicated creatures, with every distinguishing characteristic existing along a continuum that makes each of us unique. None of us are “normal”, and this is entirely “natural” – including the many nuances of our sexuality.

Scientists have long sought an explanation for homosexuality, and now a genome-wide association study published in Scientific Reports ( has found a weak association with two genes. The first, SLITRK6, is a neurodevelopmental gene on chromosome 13 that is expressed in the diencephalon, a region of the brain that differs in size in men depending on their sexual orientation. The second gene, TSHR on chromosome 14, encodes the receptor for thyroid-stimulating hormone. The authors say this “could conceivably help explain past findings...

The full text of this article can be purchased from Informit.