This archive report was first published on 4 January 2020.
Published on 29 August in Science, the study confirms earlier research that sexual preferences have a genetic component, but no single gene has a large effect on sexual behaviors.
Lead study author Andrea Ganna, a geneticist at the Broad Institute of MIT and Harvard in Cambridge, Massachusetts, emphasizes that there is no 'gay gene.'
The study used a genome-wide association study (GWAS) to analyze the genomes of hundreds of thousands of people for single-letter DNA changes called SNPs. The researchers found that genetics could explain 8–25% of the variation in sexual behavior, but the five SNPs associated with same-sex sexual behaviors collectively explained less than 1% of the variation.
According to Ganna, the results suggest that there are a lot of genes that influence sexual behavior, many of which researchers haven’t found yet. An even larger sample size could help to identify those missing variants.
However, Ganna cautions that these SNPs can’t be used to reliably predict sexual preferences in any individual because no single gene has a large effect on sexual behaviors.
The study also highlights the complexity of human sexuality, with one SNP associated with male-pattern baldness and another near a gene related to smell, which Ganna says has a role in sexual attraction.
