Journal of Sex Research, by John D. DeLamater,
Morgan SillHuman sexuality is generally an
understudied area of scientific investigation, and
researchers have been particularly neglectful of
the study of sexuality in the aging population.
Since the number of elderly persons in the U.S.
doubled from nearly 17 million in 1960 to
35 million in 2000, and is projected to reach
53.7 million by 2020 (United States Bureau of the
Census, 2002), this topic takes on particular importance.
Much of the prior research reflects a biological or medical perspective on human sexuality. It assumes that as people age, physical changes, hormonal changes, or chronic illnesses reduce or eliminate sexual desire and sexual behavior. This literature reflects the general trend toward the medicalization of human sexual functioning, which has accelerated in the past 20 years (Tiefer, 2004). It overlooks psychological and social influences on sexuality.
A Biopsychosocial Perspective
In contrast, what is needed is a biopsychosocial perspective, one that combines biological, psychological, and socio-environmental factors (DeLamater, 2002). Any approach to the study of human sexuality that stresses only one dimension, such as biology or sociology, is counterproductive (Rossi, 1994). This paper applies such a model to the understanding of sexual desire in women and men over the age of 45. The components of the model are listed in Figure 1.
Biopsychosocial Model of Sexuality
Biological Influences
Hormonal system
Vascular system
Illness/treatment
Psychological Influences
Sexual information
Attitudes toward sexual expression
Mental Health
Depression/Treatment
Social Influences
Availability of a partner
Length of relationship
Quality of relationship
Income
Among the biological influences are the hormonal and vascular systems and illnesses and associated treatments. Important psychological influences include sexual information, sexual attitudes, and mental health. Within the category of relational influences, the availability of a partner is a prerequisite for partnered sexual activity. Income is also relevant as an index of access to resources related to health, such as living standard.
We believe that biological factors provide a necessary but not sufficient condition for sexual functioning. In addition to biological capability, the person must have knowledge and attitudes supportive of sexual activity. The availability of a partner also influences sexual expression.
The purpose of this study is to examine how levels of sexual desire are associated with these biopsychosocial factors. We first discuss sexual desire. Next, we review the literature on the relationship between the biospychosocial influences and sexual desire. Then we will present data from a survey of a representative sample of 1,384 persons age 45 or older. The variables in our analyses include age, illnesses, and medication use; attitudes, expectations, and knowledge; and presence or absence of a sexual partner, education and household income.
In particular, we wanted to determine whether sexual desire declines with age, and, if it does, identify which of these factors are the main influences. We are especially interested in the impact of attitudes, which reflect the influence of cultural values and stereotypes.
Sexual Desire
There is no universally accepted definition of sexual desire. Often it is confused with other aspects of human sexuality. In fact, sexual desire can be associated with sexual behavior but is simultaneously separate from it.
Theorists and researchers in the area of sexual desire have used two main frameworks. The first and most common assumes that sexual desire is an innate motivational force (i.e., an instinct, drive, need, urge, appetite, wish, or want). The second framework emphasizes the relational aspects of sexual desire, conceptualizing desire as one factor in a larger relational context.
As early as 1886, von Krafft-Ebing (1886/1965) discussed sexual desire as a powerful "physiological law" that arose jointly from cerebral activity (e.g., using the imagination) and the pleasurable physical sensations associated with this cerebral activity. Freud, too, conceived of sexual desire as a biological fact, an innate, motivational force. Following in their footsteps, Kaplan (1977, 1979) stated that sexual desire is an appetite or drive that motivates us to engage in sexual behavior. Like other drives, such as hunger, sexual desire is regulated by the avoidance of pain and the seeking of pleasure, and it is produced by the activation of a specific neural system in the brain.
Other researchers choose to define sexual desire not as a biological force but as a cognitive or emotional experience, such as wishing or longing (Everaerd, 1988; Schreiner-Engel, Schiavi, White, & Ghizzani, 1989). According to Heider (1958), desire is a motivational state that arises from within the person and that represents the person's own wish or want. Desire is therefore a subjective, psychological condition that is not necessarily reflected in an individual's actual or potential actions.
The aforementioned theorists and researchers emphasize the intra-individual nature of sexual desire. That is, some innate biological need arising from within the body (and considered by some to be subject to learning and socialization processes) produces a subjective state of sexual desire that impels the individual to seek out or become receptive to sexual objects and experiences.
Other investigators, however, view desire as an externally generated phenomenon. Desire is located in the partner rather than in oneself since it is a feeling of being drawn to the other (Verhulst & Heiman, 1979). Sexual desire originates from an external source of stimulation located within the desired object rather than from some need arising within the desiring individual.
Levine (1987), however, argues that sexual desire is generated and influenced by both internal and external events. According to his model, sexual desire is a personal, subjective experience that is defined as "the psychobiologic energy that precedes and accompanies arousal and tends to produce sexual behavior" (p. 36). Levine believes that desire is best viewed as the product of an interaction among (a) the neuroendocrine system, which yields a biologically-based sexual drive; (b) the cognitive processes that generate the wish to behave sexually; and (c) the psychologically based, motivational processes that result in the willingness to behave sexually.
In this paper, we have operationalized sexual desire in the terms of cognitive events (sexual thoughts, sexual fantasies). Our concept of sexual desire is not associated with any overt sexual activity. We believe that thoughts and fantasies represent motivational aspects of sexual experience and therefore may serve as indirect measures of sexual desire (Sherwin, 1988).
Biological Influences
Age. Kinsey, Pomeroy, and Martin (1949) stated that of the eleven factors that are significant in understanding human sexuality, none seemed more important than age. Sexual behavior in women and men declines steadily from adolescence into older age, and to a lesser extent there is diminution in sexual desire (Maurice, 1999). Some researchers report that older adults continue to be interested in sex as long as poor health does not affect their sexual desire. In particular, aging does not appear to have any effect on female sexual desire (Masters, Johnson, & Kolodny, 1994).
However, Levine (1998) concludes that sexual desire for both women and men changes considerably in older ages. McKinlay and Feldman (1994) reported that in their study of men ages 40 to 70, sexual desire and frequency of sexual thoughts and dreams decreased with age. In Schiavi's study (1999) of healthy men ages 45 to 74 years who were living in stable sexual relationships, sexual desire decreased as age increased. Others have also found that sexual interest declines in aging women (Hallstrom & Samuelsson, 1990; Osborn, Hawton, & Gath, 1988). One cause of these conflicting results may be variation in the measure of sexual desire employed. Another may be the failure to take into account the influence of other relevant factors.Hormones. A second biological factor is sex hormones. It appears that sexual desire is influenced by androgens in men and by estrogens and androgens in women (American College of Obstetricians and Gynecologists, 2000). As one ages, there are many changes in the production and functioning of sex hormones (Morley, 2003). Women experience an almost complete cessation of the production of estradiol (principal estrogen) by the ovaries at the time of menopause; before menopause the ovaries produce 95% of estradiol (Sherwin, 1992). In the absence of estrogen, atrophic changes of the vagina occur. Decreased estrogen levels can also result in diminished vaginal lubrication, which, in turn, might cause discomfort or pain during intercourse (Maurice, 1999). Thus, cessation of sexual activity in older women may reflect the fact that intercourse is painful rather than a decline in sexual desire. In men, testosterone levels decline gradually from age 40 to age 70; the total decline in free testosterone is typically 30 percent (Schiavi, 1999).
Studies suggest that testosterone is associated with increased levels of sexual desire and enjoyment of sex in some post-menopausal women (Sarrel, 1999; Sarrel, Dobay, & Wiita, 1998; Sherwin, Gelfand, & Brender, 1985). According to several researchers, sexual desire in women is, in biological terms, more dependent on androgen levels than on estrogen levels (Anonymous, 2002; Masters et al., 1994; Vander, Sherman, & Luciano, 2001). In women, approximately 50% of testosterone is made in the adrenal glands, with the other half being produced by the ovaries during the reproductive years (Anonymous, 2002). The cessation of ovarian function that accompanies menopause does not significantly reduce the levels of androgens reaching the brain (Masters et al., 1994). In contrast to the supposed importance of androgen levels, others say that receptor number and sensitivity are more important. Even though testosterone replacement therapy (TRT) is being prescribed for sexual difficulties, data regarding its efficacy, especially in affecting sexual desire, is inconclusive at this time (American College of Obstetricians and Gynecologists, 2000; Anonymous, 2002).
Illness. Chronic disorders, such as cardiovascular disease, diabetes, arthritis, and cancer, may have negative effects on sexual functioning and response (Maurice, 1999; Schiavi, 1999). These diseases impair sexual function both directly, by acting on physiological mechanisms (by interfering with the endocrine, neural, and vascular processes that mediate sexual response) and reproductive structures, and indirectly, by limiting total body function.
Cardiovascular diseases, such as myocardial infarction, hypertension, and peripheral vascular insufficiency (atherosclerosis), are commonly associated with sexual response problems (Schiavi, 1999). Many studies have reported a loss of sexual drive in as few as 10% to as many as 70% of patients after myocardial infarction (Papadopoulos, 1989). Studies on sexual behavior after a stroke report decreased levels in sexual desire (Angeleri, Angeleri, Foschi, Giaquinto, & Nolfe, 1993; Boldrini, Basaglia, & Calanca, 1991). There are, however, methodological issues to be considered in evaluating the results of these studies, including the lack of consideration of (a) age effects and (b) the level of sexual function and desire prior to infarction. Further, all of the cited research involved treated patients, confounding the effects of disease and treatment.
Hypertension is prevalent among older adults, and it is also associated with peripheral vascular disease, myocardial infarction, and stroke (Schiavi, 1999). Although there are numerous studies on the sexual consequences of anti-hypertension treatment, there are few on sexual functioning in persons with these illnesses who are not receiving treatment (Schiavi).
Diabetes mellitus, which has vascular effects on blood vessels, is one of the most frequent systemic disorders associated with sexual problems in aging adults (Masters et al., 1994; Schiavi, 1999). Schiavi, Stimmel, Mandeli, and Rayfield (1993) found that diabetic men, screened for nondiabetic pathology, show decreased levels of sexual desire compared to age-matched healthy controls. The duration of the disease (insulin-dependent or noninsulin-dependent diabetes) and type of treatment do not appear to be significantly related to the occurrence of sexual problems (Schiavi). On the other hand, Masters et al. (1994) contend that men with diabetes do not have decreased levels of sexual desire.
Sexual functioning and response in diabetic women have been studied less extensively. However, it has been found that diabetic neuropathy, a condition that affects the nerve supply to the pelvis, can cause impaired sexual desire in women (Masters et al., 1994). Unfortunately, there are few controlled studies of the psychology of sexual dysfunction in those with diabetes (Bancroft & Gutierrez, 1996).
Arthritis in aging adults is a major cause of discomfort and disability. It has often been assumed that those with arthritis have sexual difficulties, but this has seldom been systematically investigated (Schiavi, 1999). One study of males (mean age 58) reported that there were decreased levels of sexual desire in the arthritic patients in comparison to the control group of non-arthritic men (Blake, Maisiak, Kaplan, Alarcon, & Brown, 1988).
Prostate disease occurs frequently in aging men. It is the second most prevalent cancer, present in almost 90% of men ages 80 and older, and the second most common cause of death from cancer (Masters et al., 1994; Schiavi, 1999). Sexual dysfunction is a common complication of this disease and its treatment (Jakobsson, Loven, & Hallberg, 2001). Fortunately, nerve-sparing prostatectomy has been proven to have positive effects on the sexual functioning of patients (Gralnek, Wesells, Cui, & Dalkin, 2000). Even though nerve-sparing operations can often provide preservation or recovery of sexual functioning, recovery also depends on the age of the patient (Catalona & Basler, 1993; Miyao et al., 2001). Moreover, conclusions are limited by insufficient information about sexual response and functioning prior to surgery, other diseases, and medications (Schiavi).
Medications. Numerous prescription drugs have adverse effects on sexual functioning, including antidepressant and anti-hypertension medications. Moreover, adverse drug effects have been reported much more frequently in the aging population than in the general population (Wade & Bowling, 1986). Gender differences should also be examined. The use of prescribed medications and the rate of adverse effects of drug therapy are consistently higher in female than male elderly populations (Schiavi, 1999).
Many prescription drugs cause sexual side effects. However, knowledge is limited by inadequate information on the specifics of drug action, such as how drugs are distributed, metabolized, excreted, and targeted in older persons, especially women. Medications may influence sexual responses, which include desire, by nonspecific effects on general well-being, energy level, and mood (Schiavi, 1999).
Drugs for the treatment of high blood pressure represent the single largest medication group responsible for sexual side effects. These drugs include alpha-blockers, diuretics, and calcium 2 channel blockers (Masters et al., 1994). Previous studies have shown that the incidence of drug-induced sexual dysfunction increases as men take increasing dosages of anti-hypertensive drug treatments (Levine, 1998).
Drugs used to treat psychiatric disorders can also cause sexual side effects. Antipsychotic medications, tricyclic antidepressants, monoamino-oxidase (MAO) inhibitors, and sedative drugs may contribute to decreasing levels of sexual desire (Schiavi, 1999; Segraves, 1989). However, among drugs used to treat psychiatric illnesses, the selective serotonin reuptake inhibitors (SSRIs) are perhaps the major culprit with regard to diminished sexual desire. The effects of SSRIs on sexual functioning seem strongly dose-related and are also connected to the tendency for SSRIs to accumulate over time (Rosen, Lane, & Menza, 1999).
Psychological Influences
Psychological factors are major determinants of the intensity of sexual desire. Yura and Walsh (1983) state that attitudes, knowledge, and expectations of one's self and one's sexual partner impact personal behavior. Sexual attitudes, knowledge, and sexual experiences in earlier years are closely interwoven with sexual desire (Butler, Lewis, Hoffman, & Whitehead, 1994). Negative attitudes toward sex among older women and men are common (Story, 1989). In part, these attitudes reflect America's youth-oriented culture. American popular culture equates sex appeal with the characteristics of a youthful body, such as a firm body and smooth skin (Levy, 1994). Another contributor is the emphasis on reproduction. In populations where the primary purpose of sexual intimacy is seen as reproduction, it is considered inappropriate for a post-menopausal woman to continue to be sexually active (Deacon, Minichiello, & Plummer, 1995; Levy; Story). We are especially interested in the relative impact of such attitudes on sexual desire.
Sexuality is socially and culturally constructed (Irvine, 1990; Masters et al., 1994; Stock, 1984; Tiefer, 1991, 2004). Culture provides a set of expectations, beliefs, and attitudes about sexuality, and women and men draw on these to attach meaning to their experiences. In the U.S., aging women and men's sexuality is influenced by a cultural environment that is fraught with both ageism and sexism (Abu-Laban, 1981; Sanford, 1998; Shaw, 1994). Sociocultural factors work to minimize or deny the existence or value of sexuality for older persons (Gott & Hinchliff, 2003). Cole (1988) describes her sample of menopausal-aged women as having a sense of "despair about their lives [because they were] holding an image--perhaps a male image, or a youthful image--of how sex is supposed to be."
The images available in U.S. society about sexuality and the aged are negative. Sex is seen as unseemly, even unnatural in the old. One elderly gentleman contended, "We're supposed to be asexual, and those who refuse to be so are branded dirty old men" (Stock, 1999, p. 51). The media bombards us with a plethora of sexual images, mainly those of young, energetic people. The sexuality of older women and men is rarely portrayed in a positive light (Brown, 1989; Levy, 1994). These images influence many older people's beliefs, leading to the conclusion that sex is only for the young and beautiful (Hillman & Stricker, 1994). These stereotypes and myths set in motion a self-fulfilling prophecy. Older people may withdraw from any form of sexual expression and ignore or suppress sexual desire because it is "sick," "unsuitable," or "wrong." According to Sloane (1993), many older women and men do feel asexual.
Health care providers may contribute to the silence surrounding sexuality in aging by not talking with their aging and elderly patients about sexuality issues (Fallowfield, 2002; Stead, Fallowfeld, Brown, & Selby, 2001). Some doctors do talk to their older patients about sexuality. In fact, some prescribe sexual education classes as a form of sex therapy. In a study by White and Catania (1982), the experimental groups (ages 60 to 83 years) showed significant increases in sexually permissive attitudes after attending educational classes that included information on physical, social, and psychological aspects of sexuality and aging.
Aging women and men with inadequate knowledge of sex and sexuality may be vulnerable to faulty expectations and concerns about performance (White & Catania, 1982). There is a widespread assumption that vaginal intercourse is the only "real sex" (Blank, 2000); therefore, if the person, by reason of dysfunction or disease, is unable to have intercourse, he or she may lose interest in sex. To meet the challenge of maintaining sexual activity during the aging process, couples have to make love with what they have. Hands and mouths are reliable; penises and vaginas are not. However, it is common for couples to end their sexual lives together because one or both partners believe that an erection is necessary to "get the job done" or see non-coital sex as immoral or perverse (Blank; Cogen & Steinman, 1990; Levine, 1998).
Relational Influences
The presence or absence of a sexual partner is an extremely important factor in understanding differing levels of sexual desire and activity among aging women and men. Many people consider sexual intimacy to be only or most appropriate in marriage (Levy, 1994). Many older persons are not married or no longer live with a spouse. There are 26.6 million men and 33 million women over 55; only 74% of the men and 50% of the women are married and living with a spouse (Smith, 2003). This gap in the living situation of men and women increases with age.
Marriage is the most common social arrangement within which normative sexual activity takes place (Rossi, 1994; Schiavi, 1999). Thus, the death of a spouse usually leads to the cessation of sexual behavior (Rossi). Women tend to marry older men, which is a main reason that women are more likely to be widowed. Women outlive their mates, often by a decade or more (Sanford, 1998). As a result, 40% of older women live alone, compared with 16% of older men (AARP, 1997).
According to Masters et al. (1994), many older women who are without a sexual partner for an extended amount of time drift into a state of sexual disinterest. "This is often a way of coping psychologically with their circumstances: by turning off their interest in something they don't have and see little likelihood of getting, they prevent themselves from becoming frustrated or depressed" (Masters et al., p. 479).
For those who do have a sexual partner, monotony in sexual relationships, such as predictability of sexual activities and over-familiarity with the partner, may also contribute to a loss in sexual desire (Levy, 1994). As the length of the marital relationship increases, habituation to sex with one's partner increases and frequency of sexual activities declines. Norms that limit sexual activities to marriage, combined with the habituation effect, may cause early diminution of sexual desire (Call, Sprecher, & Schwartz, 1995). One study on the relationship between women's menopausal status and sexual desire found that women who were of menopausal status had lower sexual desire compared to when they were in their 40s (No women were on hormone replacement therapy or had a surgical menopause, and all had a partner.) (Avis, Stellato, Crawford, Johannes, & Longcope, 2000). Past research also found that married women who reported lower levels of desire were more likely to agree that interest in sex declines with age, and were more likely to say that they were less aroused now than when they were in their 40s (Avis et al., 2000).
On the other hand, the results of the Duke studies (Pfeiffer, Verwoerdt, & Davis, 1972; Verwoerdt, Pfeiffer, & Wang, 1969) found that marital status had little effect on sexual interest. In data from the Consumers Union survey on sex and aging involving 4,246 men and women over the age of 50, the majority of happily married women and men rated sex as important in marriage, while 54 percent of unhappily married wives rated sex as being "of little importance" (Brecher & Editors, 1984). These results suggest that satisfaction with the relationship may be an important influence on desire; results such as those reported by Avis may reflect marital unhappiness rather than loss of desire.
Sex is important for many unmarried older adults, too (Masters et al., 1994). Some fulfill their desire for sexual intimacy within a long-term committed relationship. We have little information about the sexual activity of older persons who live alone.
Level of sexual desire.
Level of sexual desire was measured by two questions: "How frequently do you feel sexual desire? This feeling includes wanting to have sexual experiences, planning to have sex, and feeling frustrated due to lack of sex," and "How frequently do you have sexual thoughts, fantasies, or erotic dreams?" Each question was answered using an 8-point scale from 1 (more than once a day) to 8 (not at all). We created an index of desire by computing the average of the numeric responses to these two items. If the participant answered neither item, no score was computed. The reliability (alpha) of this scale was .86 for men and .87 for women.
