Stop calling it a choice: Biological factors drive homosexuality

  Across cultures, 2% to 10% of people report having same-sex relations. In the U.S., 1% to 2.2% of women and men, respectively, identify as gay. Despite these numbers, many people still consider homosexual behavior to be an anomalous choice. However, biologists have documented homosexual behavior in more than 450 species, arguing that same-sex behavior is not an unnatural choice, and may, in fact, play a vital role within populations.

  In a recent issue of Science magazine, geneticist Andrea Ganna at the Broad Institute of MIT and Harvard, and colleagues, describe the largest survey to date for genes associated with same-sex behavior. By analyzing the DNA of nearly half a million people from the U.S. and the U.K., they concluded that genes account for between 8% and 25% of same-sex behavior.