How common is masturbation in young adults?

Answer 1

Almost all young boys and men m********e regularly, from as little as once or twice a month to several times a day. Even older adult males who have s*x regularly often still m********e, sometimes even as part of s*x with their partners. Masturbation is normal and healthy, even when done several times a day, as long as it does not interfere with other aspects of normal living.

I'll leave it to someone else to comment on young women.