"In their review of sex differences, Baumeister, Catanese, and Vohs (2001) report a higher level of sex drive in men regardless of the measure used for investigation. Men think about sex more often than women, they experience spontaneous sexual arousal more often, are more readily aroused by visual stimuli, more focused on the genitals and on achieving orgasm, less easily distracted during coitus, prefer a greater variety of sexual practices, masturbate more frequently, find it harder to forego sexual activity for any period of time, and are more prepared to make sacrifices to obtain sex. They rarely suffer from hyposexual desire disorder.
Sexual desire in couples
In long-term relationships, men report a desire for a higher frequency of sex than their female partners at every stage of the relationship. This was found in the early studies by Kinsey, Pomeroy, and Martin (1948) and in virtually every study since (Baumeister et al., 2001; Oliver & Hyde, 1993). Men are typically more dissatisfied with their sex lives and women more dissatisfied with their partner’s emotional responsiveness and ability as providers (Rhyne, 1981). Even in the age group 60-80 years, 52% of men but only 16% of women consider sex to be important (Bergstrom-Walan & Nielsen, 1990). In a survey of couples who had been married for 20 years, Ard (1977) found that wives were satisfied with the amount of sex they had, but husbands desired greater frequency. Husbands reported more enjoyment from sex than wives and they underestimated the sexual desire of their wives while their wives overestimated their husband’s preferred frequency of sex. Julien, Bouchard, Gagnon, and Pomerleau (1992) secured reports from both partners of middle class married couples from Montreal, Canada. Husbands desired a higher frequency of sex than they actually experienced, and their wives underestimated their husband’s preferred frequency of sex - contrary to the results found by Ard (1977). Furthermore, husbands perceived themselves to be more interested in sex and gratified by sex than their wives. In a study of couples, Julien et al. (1992) conclude that both partners perceive a husband´s sexual initiative as being determined by an internal need, and a wife´s sexual initiative by the desire to display proof of her love. In an Australian study of young adults, men wanted more frequent sex than women at every stage of dating (McCabe, 1987). With increasing involvement in the relationship this discrepancy decreased but never disappeared. Women seem to require a larger dose of emotional intimacy in order to generate maximum passion, whereas men may reach a high level of passion with much less emotional intimacy (Vohs & Baumeister, 2004).
Love and sexual desire
Can there be a situation in which the sexual desire of a woman equals or exceeds that of a man? Baumeister and Bratslavsky (1999) speculate about such a situation: The love phase at the beginning of a relationship, when intimacy is increasing at a fast rate. Sexual desire, especially in women, so they speculate, is more sensitive to changes than to absolute levels of intimacy. In a blossoming relationship it responds to the acceleration of commitment. This would be expected mostly in newly-formed relationships of adolescents and young adults, and in fact Davies, Katz, and Jackson (1999) showed that in a sample of 20-year-olds who had been dating for about two years no sex differences in sexual desire occurred. A similar result was reported by Klusmann (2002) for German students aged 19-30 years. Measures of sexual desire did not differ between the sexes in the first two years of a relationship. In couples involved for a longer duration, female sexual motivation continually dropped while male sexual motivation stayed the same.
Duration of a relationship overrules age in predicting sexual activity
In a British survey of a large, nationally representative sample (n = 16700), duration of relationship was more strongly related to sexual activity than age. When only relationships in their early stages (up to two years) were considered, frequency of sex was fairly constant, independent of age, with a median of 8-10 acts of sexual intercourse per month for women and 9-10 for men, in age groups ranging from 16 to 44 years. Only in age group 45-59 years did the median decrease (Johnson, Wadsworth, Wellings, & Field, 1994, p. 155). In a student sample with an age range of 19-30 years and a median duration of relationship of three years, no age effect remained for both sexes after duration of relationship was introduced into the regression equation to predict sexual activity (Klusmann, 2002). A similar result emerged in a nationally-representative German interview study with three age groups: 30, 45, and 60 years (Schmidt, Matthiesen, Dekker, & Starke, 2006). When a middle-aged couple divorces and starts over with new partners, the frequency of intercourse will be high again in both sexes, independent of age (Call, Sprecher, & Schwartz, 1995; Vohs & Baumeister, 2004). This strong link of sexual frequency to the duration of the relationship suggests an instrumental role of sex for the formation of a relationship. However, there is no obvious reason to expect long-term maintenance of a relationship being less dependent on sexual activity than its formation and so the question remains why sexual activity decreases after about two years.
Sociosexual Orientation
Men are more willing than women to engage in sexual relations when they feel no emotional involvement (Clark & Hatfield, 1989; Townsend, 1995). In a meta-analysis, Oliver and Hyde (1993) found the attitude toward casual sex to differ between men and women with the second largest effect size - the largest was found in masturbation frequency. An updated meta-analysis 17 years later delivered the same rank order of sex differences (Petersen & Hyde, 2010). Only when the use of pornography was included did masturbation descend to rank two and the attitude toward casual sex to rank three. Sociosexual orientation (SO) refers to a personality trait ranging between two poles: unrestricted - a willingness to engage in sexual relationships without commitment or emotional closeness and restricted - a reluctance to engage in uncommitted sex (Simpson and Gangestad, 1991)...
Women who are interested in having short-term sexual relationships report greater interest in men´s physical attractiveness and are more sensitive to differences in symmetry (Gangestad & Simpson, 2000). Mikach and Bailey (1999) contrasted two groups of women who differed strongly in their number of lifetime sex partners. Women with many sex partners as compared to women with fewer sex partners reported their first sexual experience five years earlier, had a lower waist-to-hip ratio, behaved more like boys during childhood, were rated to be more masculine in their physical appearance and their behavior, and were more unrestricted in SO. There was no indication that women who had more sex partners were lower in mate value or endured greater childhood stress than women with fewer sex partners.
Much of the research on SO just particularizes and supplements the definition of the concept: Unrestricted individuals avoid sustained emotional intimacy, lack warmth and the capacity to form close relationships, they like the benefits of short- time affairs and sexual experimenting, place high value on physical attractiveness, tend to be emotional immature, egocentric, and lacking in self insight and agreeableness (Simpson, et al., 2004)...
People tend to choose mates according to their own SO. In student samples, unrestricted SO is associated with a preference for sexual attractiveness and social visibility in a potential mate, whereas restricted SO is associated with a preference for kindness, responsibility, and faithfulness (Simpson & Gangestad, 1991). These preference discrepancies held even after statistically controlling for assortative mating.
Garcia and Markey (2007) showed that romantic partners were generally matched in the prior number of sex partners. Discrepancy in prior number of sex partners was associated with lower levels of love, satisfaction, and commitment in the relationship when the partners were married, but not when they were just cohabitating.
Differences in SO are expected to give rise to conflict over infidelity within a couple but not to conflict over the frequency of sex, because SO seems to be unrelated to interest in sexual activity with the committed partner (Simpson & Gangestad, 1991)...
Self-reported motivations for having sex
Meston and Buss (2007) investigated sexual motivation with an open-ended prompt for participants to write down reasons for sexual intercourse. From the collection of anecdotal responses, 237 items reflecting possible reasons were abstracted and presented to a larger sample of students. Both women and men most frequently endorsed feelings of attraction as a reason for having sex. Of the top 25 items, 20 were checked by men and women with similar frequency (e.g., "I wanted to show my affection."). Men exceeded women in reasons having to do with physical attraction, pleasure seeking, and ego-boosting, whereas women exceeded men in endorsing love as a reason to have sex.
The 237 items were grouped into four domains: (1) physical (stress reduction, pleasure, physical desirability, experience seeking), (2) goal attainment (resources, social status, revenge, utilitarian motives), (3) emotional (love and commitment), (4) insecurity (selfesteem boost, duty or pressure, mate guarding). Contrary to expectation, men and women did not differ in the subfactor "emotional (love and commitment)".
Stated reasons for having sex ranged from trivial pursuits (e.g., because of a bet) to magnificent obsession (e.g., to be closer to god). The authors pursued this descriptive approach in a popular science book (Meston & Buss, 2009), which parallels the Hite report (Hite, 1981) but with input via internet instead of letters to a magazine and a framework of evolutionary theory instead of feminism. They used an online questionnaire to ask women if they had sex for one or more of the 237 reasons assembled from an earlier study of anecdotal responses. About 1000 women described their experiences and these descriptions were compiled into an account of the many facets of sexual motivation"
--- Sexual Motivation in Mateships and Sexual Conflict / Dietrich Klusmann