But it is nice to have verification:
In the three-part report published by The New Atlantis, Lawrence Mayer, a scholar-in-residence at Johns Hopkins University’s psychiatry department and a professor of statistics and biostatistics at Arizona State University, and Paul McHugh, a professor of psychiatry and behavioral sciences at Johns Hopkins, take on prevailing claims that sexual orientation and gender dysphoria are caused by natural traits.
Additionally, the scholars challenge the claim that discrimination and social stigma is the sole reason why those with same-sex attractions or transgender identity suffer higher rates of mental health problems.
In the first part, the report argues that there is insufficient evidence to claim that heterosexual, homosexual or bisexual attractions are an innate trait that people are born with.
The report goes into detail about past epidemiological studies that have found a modest association between genetic factors and sexual orientation and behaviors. However, the report states that such studies have not been able to provide significant evidence “pointing to particular genes.”
You can read the rest at the link above.