From Encyclopedia of Sex and Sexuality
Sex therapists frequently find that their clients are concerned that the frequency with which they engage in sexual intercourse may not be “normal”: that is, they believe they are having less sex than they should or than is “appropriate” or “healthy.” Still others, though satisfied with the frequency of sexual intercourse in their lives, are curious about how often others have sex. This is evidenced by interest in the frequent “sex surveys” in popular magazines.
With respect to marital happiness and sexual satisfaction, there is no normal or correct frequency of intercourse. As long as both partners are happy and satisfied with how often they engage in sex, the frequency of their activity is normal and appropriate for them. Whether they have sex twice a day or twice a month is a matter for their own libidos, desires, and preferences. It is only when one or both or the partners is dissatisfied with the frequency of intercourse that it may be an issue to bring to a sex therapist.
Rates of coital frequency are not easy to compare because they are affected by many factors. The most obvious is the availability of a partner. Therefore, the most useful and reliable statistics are those based on samples of married persons who, presumably, all have partners for sex. Consistently, these studies have shown that the frequency of sexual intercourse, even for married persons, does decline with age. However, for older persons who divorce or become widowed and then remarry, coital frequency may increase for the first few years of their new marriage.
Based on research data collected in 1948 and 1953, Alfred Kinsey reported that the frequency of sexual intercourse for persons aged sixteen to twenty-five was 2.45 times a week, dropping down to .5 per week for those over age fifty-five:
A more recent (1984) study by Consumers Union of sexual behavior and aging among persons aged fifty and older found that among the 4,246 respondents, 28 percent of the 1,016 married women reported having sex with their spouses more than once a week, as did 25 percent of the 1,515 married men. While the median frequencies were not presented, the material presented in this study indicates that changes in social and personal attitudes favor the acceptance of full sexuality among the elderly.
Frequency of sexual intercourse is at its highest during early adulthood for hormonal reasons and because younger persons are in the early stages of the marriage cycle. When comparing single and married individuals, however, the image of “swinging singles” is not borne out by reported frequency of intercourse. In a recent national study, Drs. Janus and Janus report that “…there is consistent confirmation of the fact that, although single and divorced people may have a greater variety of sexual partners, they do not have sex with the frequency that married persons do. Marrieds’ easier accessibility to sex partners obviously affects these results.” In presenting the frequency of all sexual activity, they report that 64 percent of all singles claim to have sex at least once a week compared with 85 percent of married people.