According to Wu Ying-chun, heredity usually makes some people's scalp hair follicles liable to react abnormally to male hormones, which is why the baldness rate among men is as high as 40 percent, and only eunuchs are totally immune; but occasionally women may also "strike lucky," often after the menopause, due to reduced estrogen.
吳英俊表示，遺傳主要是造成有些人頭皮的毛囊較易對男性荷爾蒙起異常反應，由此所引起的禿頭在一般男人中所佔的比率高達百分之四十，只有太監能夠完全免疫；不過偶爾女性也會「中獎」，常發生在停經後，因為雌黃激素減少所致。