Human genitals

many children are punished or made to feel guilty for touching their genitals. This is unfortunate because masturbation itself is harmless. Typically

。人在身高及體重上的成長在青春期的前半段會加速進行，一直進行到發育為成人時為止。男孩和女孩在青春期之前，其生理差異主要只在性器官（英语：Human genitals）。青春期一般是在十歲到十六歲之間出現，不過也會因個人而不同。女孩青春期開始的主要標誌是初潮（第一次的月經），平均是在十二歲到十三歲時出現。

Masturbation refers to all solo forms of self-stimulation focusing on the genitals. Masturbation practices vary widely depending upon the individual's body

Ida; Mooyaart, Eduard. Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal. BMJ. 1999, 319 (7225): 1596–600

 30–33. Nnaemeka 2005, pp. 38–39. Sara Johnsdotter and Birgitta Essén, "Genitals and ethnicity: the politics of genital modifications" （页面存档备份，存于互联网档案馆）