The concentration of male hormones in the womb may impact the development of the “mating center” of the brain. In addition, genetic studies of identical and non-identical twins strongly suggest that human genetics plays an important role. Less research has been done regarding female homosexuality; however there is also evidence of genetically linked biological differences.
Wingi wa hormones za kiume tumboni mwa mama hubadili sehemu ya ubongo inayoshughulikia jinsia ya ushiriki wa ngono. Pamoja na hayo, utafiti wa mapacha wanaofanana na wasio fanana unadhihilisha yakwamba genetics huchangia mahali pakubwa. Utafiti wa masege (lesbians) hujafanywa sana; lakini kuna ushahidi kuwa maumbile yao ya genetics ni tofauti.