"Currently, there is a renewed interest in searching for biological etiologies for homosexuality. However, to date there are no replicated scientific studies supporting any specific biological etiology for homosexuality."
Born or Bred? Science Does Not Support the Claim That Homosexuality Is Genetic
The American Psychiatric Association is trying to be politically correct as they're afraid saying homosexuality has a genetic component would lead some people to label it a "disease" that needs to be cured with drugs or gene therapy rather than a genetic variation similar to having green eyes or being left-handed.