“LONDON, England (Reuters) — Genetic factors, along with cultural and early experiences, influence male homosexuality, Italian scientists said on Wednesday.”
One study is by no means conclusive proof. This particular study evaluated 198 men and 4,600 relatives.
Few exgays, even those who successfully “change” their behavior, seem to be able to change their same-sex sexual attractions. I would like to see a great deal more study of non-genetic, biological factors.