Frequency of masturbation is determined by many factors, e.g., one's resistance to sexual tension, hormone levels influencing sexual arousal, sexual habits, peer influences, health and one's attitude to masturbation formed by culture.Medical causes have also been associated with masturbation.
Different studies have found that masturbation is frequent in humans. Alfred Kinsey's studies have shown that 92% of men and 62% of women have masturbated during lifespan.Similar results have been found in British national probability survey. It was found that 95% of men and 71% of woman masturbated at some point in their lives. 73% of men and 37% of woman reported masturbating in the four weeks before their interview, while 53% of men and 18% of woman reported masturbating in previous seven days.
"Forty-eight female college students were asked to complete a sexual attitudes questionnaire in which a frequency of masturbation scale was embedded. Twenty-four of the women (the experimental group) then individually viewed an explicit modeling film involving female masturbation. One month later, all subjects again completed the same questionnaire. Subjects in the experimental group also completed a questionnaire evaluating aspects of the film. Results indicated that the experimental group reported a significant increase in the average monthly frequency of masturbation, as compared to the control group. This same group, however, reported that the film had no effect on sexual attitudes or behavior."
A 2004 survey by Toronto magazine NOW was answered by an unspecified number of thousands.The results show that an overwhelming majority of the males – 81% – began masturbating between the ages of 10 and 15. Among females, the same figure was a more modest majority of 55%. (Note that surveys on sexual practices are prone to self-selection bias.) It is not uncommon however to begin much earlier, and this is more frequent among females: 18% had begun by the time they turned 10, and 6% already by the time they turned 6. Being the main outlet of child sexuality, masturbation has been observed in very young children. In the book Human Sexuality: Diversity in Contemporary America, by Strong, Devault and Sayad, the authors point out, "A baby boy may laugh in his crib while playing with his erect penis (although he does not ejaculate). Baby girls sometimes move their bodies rhythmically, almost violently, appearing to experience orgasm."
A Canadian survey of Now magazine readers (cited above), has it that the frequency of masturbation declines after the age of 17. Many males masturbate daily, or even more frequently, well into their 20s and sometimes far beyond. This decline is more drastic among females, and more gradual among males. While females aged 13–17 masturbated almost once a day on average (and almost as often as their male peers), adult women only masturbated 8–9 times a month, compared to the 18–22 among men. Adolescent youths report being able to masturbate to ejaculation around six times per day, though some men in older middle age report being hard pressed to ejaculate even once per day. On the other hand healthy 21-28 year old males are able to masturbate at least 8-10 times per day if they are not stressed. The survey does not give a full demographic breakdown of respondents, however, and the sexual history of respondents to this poll, who are readers of an urban Toronto lifestyle magazine, may not extend to the general population.
It appears that females are less likely to masturbate while in a heterosexual relationship than men. Popular belief asserts that individuals of either sex who are not in sexually active relationships tend to masturbate more frequently than those who are; however, much of the time this is not true as masturbation alone or with a partner is often a feature of a relationship. Contrary to conventional wisdom, several studies actually reveal a positive correlation between the frequency of masturbation and the frequency of intercourse. One study reported a significantly higher rate of masturbation in gay men and women who were in a relationship.
Among some cultures, such as the Hopi in Arizona, the Wogeno in Oceania, and the Dahomeans and Namu of Africa, masturbation is encouraged, including regular masturbation between males. In certain Melanesian communities this is expected between older and younger boys. One interesting twist is the Sambia tribe of New Guinea. This tribe has rituals and rites of passage surrounding manhood which involve frequent ejaculation through fellatio. Semen is valued and masturbation is seen as a waste of semen and is therefore frowned upon even though frequent ejaculation is encouraged. The capacity and need to ejaculate is nurtured for years from an early age through fellatio so that it can be consumed rather than wasted. Semen is ingested for strength and is considered in the same line as mothers' milk.
Other cultures have rites of passage into manhood that culminate in the first ejaculation of a male, usually by the hands of a tribal elder. In some tribes such as the Agta, Philippines, stimulation of the genitals is encouraged from an early age. Upon puberty, the young male is then paired off with a "wise elder" or "witch doctor" who uses masturbation to build his ability to ejaculate in preparation for a ceremony. The ceremony culminates in a public ejaculation before a celebration. The ejaculate is saved in a wad of animal skin and worn later to help conceive children. In this and other tribes, the measure of manhood is actually associated more with the amount of ejaculate and his need than penis size. Frequent ejaculation through masturbation from an early age fosters frequent ejaculation well into adulthood.
Masturbation is becoming accepted as a healthy practice and safe method for sharing pleasure without some of the dangers that can accompany intercourse. It is socially accepted and even celebrated in certain circles. Group masturbation events can be easily found online. Masturbation marathons are yearly events and are occurring across the globe. These events provide a supportive environment where masturbation can be performed openly among young and old without embarrassment. Participants talk openly with onlookers while masturbating to share techniques and describe their pleasure.