Most continue to do it simply because it feels good. Children may masturbate as often as several times each day, or as seldom as once a week. Masturbation occurs more often when they are sleepy, bored, watching television, or under stress. Some children masturbate frequently because they are unhappy about something, such as the birth of a sibling or having their pacifier taken away. Others are reacting to punishment or parental pressure to stop masturbating, which only makes them do it more.
Masturbation has no medical causes.
Once a child discovers masturbation, he will seldom stop doing it completely. He may do it less frequently if power struggles or unhappy feelings are remedied. By 5 or 6 years of age, most children have learned some discretion and will masturbate only in private. Masturbation may continue through childhood and becomes almost universal at puberty in response to the normal surges in hormones and sexual drive. Masturbation does not cause any physical injury or harm to the body.