IN 1993 A region of the human genome called Xq28 was linked to male homosexuality, and the controversial notion of a “gay gene” was born. Those research findings have not been replicated. But it was never going to be that simple: decades of genetic research have shown that almost every human characteristic is a complex interplay of genes and environmental factors. A new study, published in Science this week, confirms that this is the case for human sexuality, too.
The study, the largest ever into this difficult topic, was conducted by an international group of scientists working with 23andMe, a personal genomics firm. It used what is called a genome-wide association study (GWAS) on 408,995 individuals in the UK Biobank, a British health resource, and 68,527 American 23andMe users—all of whom remained anonymous and consented to the study.