A new study has shed light on homosexuality, and why it might have evolved. From dolphins to chimpanzees, same–sex behaviours (SSBs) are common among thousands animals, but until now, why they might ...

Homosexuality has a genetic component. If a man's brother is gay, he is four times as likely to also be gay. How can homosexuality be genetic, however, if homosexuals don't reproduce? Two recent ...

Some 60 primate species, including baboons, chimpanzees and vervet monkeys, express homosexuality, according to a new study that sheds further light on the evolutionary origin of same-sex intimacy.

A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Over the years, Pew Research Center has asked Americans about the morality of ...