Many researchers believe sexual orientation is a natural variant like eye or hair color and right or left handedness, since it is seen in nearly all species.
Watafiti wengi wanaamini kuwa mwelekeo wa jinsia ya ngono ni tofauti ya kawaida ya maumbile kama vile rangi ya macho au nywele, aidha, uzoefu wa matumizi ya mkono wa kulia au kushoto, kwa sababu uhanithi hupatikana kwa takriban wanyama wote duniani.