Sexual desire is a motivational state and an interest in “sexual objects or activities, or as a wish, need, or drive to seek out sexual objects or to engage in sexual activities”. Sexual desire has been referred to by many different names such as libido, sexual drive, sexual motivation, sexual interest, and lust. It is an aspect of a person's sexuality, which varies significantly from one person to another, and also varies depending on circumstances at a particular time.
Sexual desire may be the “single most common sexual event in the lives of men and women”. Sexual desire is a subjective feeling state that can “be triggered by both internal and external cues, and that may or may not result in overt sexual behavior”. Sexual desire can be aroused through imagination and sexual fantasies, or perceiving an individual that one finds attractive. Sexual desire is also created and amplified through sexual tension: which is caused by sexual desire that has yet to be consummated. 
Sexual desire can be spontaneous or responsive. Sexual desire is dynamic, can either be positive or negative, and can vary in intensity depending on the desired object/person. The sexual desire spectrum is described by Stephen B. Levine as: aversion --> disinclination --> indifference --> interest --> need --> passion.
The production and use of sexual fantasy and thought is an important part of properly functioning sexual desire. Some physical manifestations of sexual desire in humans are; licking, sucking, puckering, and touching the lips, as well as tongue protrusion.
Theorists and researchers have usually employed two different frameworks in their understanding of human sexual desire. The first is a biological framework where sexual desire comes from an innate motivational force like “an instinct, drive, need, urge, wish, or want”. Also known as sex drive. Second, a socio-cultural theory where desire is conceptualized as one factor in a much larger context (i.e. relationships nested within societies, nested within cultures). In the biological approach, sexual drive is likened to other biological drives such as hunger, where an individual will seek out food, or in the case of desire – pleasure, in order to reduce or avoid pain. Sex drive can be thought of as a biological need or craving that inspires individuals to seek out and become receptive to sexual experiences and sexual pleasure. However, members of all species (including humans) will not seek to engage in sexual activity with any conspecific, attraction plays a large role in sexual desire. Incentive motivation theory exists under this framework. This theory states that the strength of motivation towards sexual activity, depends on the strength of the stimuli (immediacy of stimuli), and if satiety is achieved, the strength of the stimuli/incentive will be increased in the future. Sex drive is strongly tied to biological factors such as “chromosomal and hormonal status, nutritional status, age, and general health”. Sexual desire is the first phase of the human sex response cycle. The traditional model for the human sexual response cycle can be represented as: Desire --> Arousal --> Orgasm --> Resolution. Sexual desire, though a part of the sexual response cycle, is believed to be distinct and separate from genital sexual arousal. It has also been argued that sexual desire is not a distinct phase in sexual response. Rather, it is something that persists through arousal and orgasm and can even persist after orgasm. Although orgasm might make it difficult for a man to maintain his erection or woman continue with vaginal lubrication, sexual desire can persist nevertheless.
In the sociocultural framework, sexual desire would indicate a longing for sexual activity for its own sake, not for any other purpose than purely for enjoyment and one’s own satisfaction or to release some sexual tension. Sexual desire and activity could also be produced to help achieve some other means or to gain some other rewards that may not be sexual in origin, like increased closeness and attachment between partners. Sexual desire is not an urge; this may imply that individuals have more of a conscious control of their own desire. That being said, sociocultural influences may push males and females into gender-specific roles where the use of social scripts dictating the appropriate feelings and responses to sexual desire and activity are expected. This may lead to conflict where an individual’s wants may be unfulfilled due to the anticipated social consequences of their actions, causing frustration. Some theorists suggest that the experience of sexual desire may be socially constructed. However, some argue that although sociocultural factors are very influential over the experience of sexual desire, they don’t play a large role until after biological initially influences desire. Another view is that sexual desire is neither a social construction nor a biological drive. According to James Giles, it is rather an existential need that is based on the sense of incompleteness that arises from the experience of being gendered.
There are many researchers who believe that stressing any single approach to the study of human sexuality and excluding others is not logical and counterproductive. It is the integrations of and interaction between multiple approaches and disciplines that will allow us the most comprehensive understanding of human sexuality from all angles. One single approach may provide necessary factors for studying desire, but it is not sufficient. Sexual desire can manifest itself in more than one way; it is a “variety of different behaviours, cognitions, and emotions, taken together”. Levine suggests that sexual desire has three components which link several different theoretical perspectives together.
- Drive – The biological component. This includes anatomy and neuroendocrine physiology.
- Motivation – The psychological component. This includes the influences of personal mental states (mood), interpersonal states (e.g. mutual affection, disagreement), and social context (e.g. relationship status).
- Wish – The cultural component. This considers cultural ideals, values, and rules about sexual expression which are external to the individual.
Sex differences in sexual desire
In early life, usually just before puberty, males are said to be quite flexible regarding their “preferred sexual incentive”, although they later become inflexible. Females on the other hand remain flexible throughout their life cycle. This change in sexuality due to sensitivity to variations in situational, cultural, and social factors is called erotic plasticity. Otherwise, we know very little about the feelings of sexual desire and sexual arousal in prepubertal children or whether any feelings they may have can be comparable to what they would experience later on in life as an adult. However, we do know that boys typically experience and commence sexual interest and activity before girls do.
Men, on average, have significantly higher sex drives and desire for sexual activity than women do; this also correlated with the finding that men, on average, have a larger total number of lifetime sexual partners. Sex drive was also related to sociosexuality scores, where the higher the sex drive the less restricted the sociosexual orientation, or the willingness to have sex outside of a committed relationship. This was especially the case for women. Lippa utilized data from a BBC internet survey to examine cross-cultural patterns in sex differences for three traits; sex drive, sociosexuality, and height. These three traits all showed consistent sex differences across nations, although women were found to be more variable than men in their sex drive. On average, male sexual desire remains stronger, more frequent, and longer into the life cycle than women’s. Though women do not experience sexual desire as often as men, when they do, the intensity of the experience is equal to that of men. Societal perceptions of men and women in addition to perceptions about acceptable sexual behaviour (e.g. men are more sexual and sometimes insatiable while women should be more reserved and almost nonsexual) may also contribute to expressed levels of sexual desire and expressed sexual satisfaction. DeLamater and Sill found that affect and feelings towards the importance of sexual activity can affect levels of desire. In their study, women who said that sexual activity was important to the quality of their lives and relationships demonstrated low desire, while women who placed less emphasis on sexual activity in their lives demonstrated high desire. Men also presented similar results. These findings were reflected in a Conaglen and Evans study where they assessed whether sexual desire levels influence emotional responses and cognitive processing of sexual pictorial stimuli. They found that women with lower sexual desire responded to sexual stimuli in the picture recognition task more quickly but rated the sexual images as less arousing and less pleasant than the other desire groups.
It has been found that women can become physically aroused when presented with explicit sexual imagery and stimuli without experiencing psychological desire or arousal. This led to 97% of women in a study reporting that they have had sexual intercourse without experiencing sexual desire while only 60% of the men reported the same thing. Also, women may form a more significant association between sexual desire and attachment than men. Women may be more prone to desire fluctuation due to the many phases and biological changes the woman’s body endures through a life cycle; menstrual cycle, pregnancy, lactation, menopause, and fatigue. Though these changes are usually very small, women seem to have increased levels of sexual desire during ovulation while during menstruation they experience a decreased level of sexual desire. In women, an abrupt decline in androgen production can cause cessation of sexual thoughts and the failure to respond to sexual cues and triggers which previously would elicit sexual desire. This is seen especially in postmenopausal women who have low levels of testosterone. Doses of testosterone given to women transdermally have been found to improve levels of sexual desire and sexual functioning.
Older individuals are less likely to declare themselves as being at the extremes of the sexual desire spectrum. By the time that individuals reach middle and old age there is a natural decline in sexual desire, sexual capacity, and the frequency of sexual behaviour. DeLamater and Sill found that the majority of men and women do not officially report themselves as having low levels of sexual desire until they are 75 years old. Many would attribute this lull to partner familiarity, alienation, or preoccupation with other non-sexual matters such as social, relational, and health concerns.
Measuring and assessing sexual desire
Properly defining sexual desire is always a challenge as it can be conceptualized in many different ways. One must take into account the definition used by clinicians in the American Psychiatric Association's Diagnostic and Statistical Manual IV-TR (DSM-IV-TR) as well as what men and women understand their own desire to be. The difficulty of not having a single, agreed-upon definition that outlines the parameters of “normal” versus “hypoactive” levels of desire creates challenges in the measurement of sexual desire and in the diagnosis of sexual desire disorders.
Many researchers seek to assess sexual desire through examining self-reported data and observing the frequency of participants’ sexual behaviour. This once again poses a problem for many researchers as this method of assessment is only emphasizing the behaviour aspects of sexual desire and is not taking into account the participants’ cognitions or biological influences that motivate them to seek out and become receptive to sexual opportunities.
Several scales have been developed in recent years to measure the various factors influencing the development and expression of sexual desire. The Sexual Desire Inventory (SDI) is a self-administered questionnaire meant to measure sexual desire. This scale defines sexual desire as “interest in or wish for sexual activity”. The SDI measures the individual’s thoughts as well as actual experiences. Fourteen questions assess the strength, frequency, and importance of an individual’s desire for sexual activity with others and by themselves. As a result, the SDI proposes that desire can be split into two categories; dyadic and solitary desire. Dyadic desire refers to “interest in or a wish to engage in sexual activity with another person and desire for sharing and intimacy with another” while solitary desire refers to “an interest in engaging in sexual behaviour by oneself, and may involve a wish to refrain from intimacy and sharing with others”.
The Sexual Interest and Desire Inventory-Female (SIDI-F) was the first validated instrument developed to specifically assess severity in Hypoactive Sexual Desire Disorder (HSDD) or to assess change in response to treatment for the disorder in females. The SIDI-F consists of thirteen items which assess the female’s satisfaction with her relationship, her recent sexual experiences both with her partner and alone, her enthusiasm, desire, and receptivity for sexual behaviour, distress over her level of desire, and arousal. With a maximum score of 51 on the scale, higher scores represented increased levels of sexual functioning.
Factors affecting sexual desire
Levels of sexual desire may fluctuate over time due to internal and external factors.
Social and relationship influences
One’s social situation can refer to the social circumstances of life, the stage of life one is in, the state of one’s relationship with a partner, or even if there is a relationship at all. Whether people think that their experience of desire or lack of experience is problematic depends on special kinds of social circumstances such as the presence or absence of a partner. As social beings, many humans seek out lifetime partners and wish to experience that celebrated connection and intimacy. Sexual desire is essential to romantic attraction and relationship development. The experience of desire can ebb and flow with the passing of time, with increasing familiarity for one’s partner, and with the changing of relationship dynamics and priorities. For more information please view Sexual Desire and Intimate Relationships.
Sexual desire disorders
There are currently two Sexual Desire Disorders in the Diagnostic and Statistical Manual IV-TR (DSM-IV-TR) which affect men and women alike. The first is Hypoactive Sexual Desire Disorder (HSDD). HSDD is currently defined by the DSM as “persistently or recurrently deficient (or absent) sexual fantasies and desire for sexual activity” which causes “marked distress or interpersonal difficulty”. However, this definition has been met with some disagreement in recent years as it places too much emphasis on Sexual Fantasy which are usually used to supplement sexual arousal. As a result, a group of sexuality researchers and clinicians have recently proposed the addition of Sexual Desire/Interest Disorder (SDID) to the DSM in hopes that it may encompass sexual desire concerns specifically in women more accurately. SDID is defined by low sexual desire, absent sexual fantasies, and a lack of responsive desire.
The second Sexual Desire Disorder in the DSM is Sexual Aversion Disorder (SAD). SAD is defined as “persistent or recurrent extreme aversion to, and avoidance of, all or almost all, genital sexual contact with a sexual partner”. However, some have questioned the placement of SAD within the sexual dysfunction category of the DSM and have called for its placement within the Specific phobia grouping as an Anxiety Disorder. Both HSDD and SAD has been found to be more prevalent in females than males, this is especially the case in SAD. However, on a spectrum of severity, HSDD would be considered less severe than SAD.
On the opposite end of the Sexual Desire Disorder spectrum is Hypersexual disorder. According to the proposed revision to the DSM which will include Hypersexual Disorder in the appendix of future publications, Hypersexual Disorder is defined as “recurrent and intense sexual fantasies, sexual urges, and sexual behavior” where the individual is consumed with excessive sexual desire and repeatedly engages in sexual behaviour in response to “dysphoric mood states and stressful life events”. Hypersexual Disorder is currently associated with sexual addiction and sexual compulsivity.
A serious or chronic illness can have an enormous effect on the biological drive and the psychological motivation for sexual desire and sexual behaviour. With poor health, an individual may be able to experience some desire but does not have the motivation or strength to have sex. Physical and mental well-being is crucial to successful and satisfying sexual expression. Chronic disorders like cardiovascular disease, diabetes, arthritis, enlarged prostates (in men), Parkinson's disease, and cancer can have negative influence over sexual desire, sexual functioning, and sexual response. In the case of diabetes, especially in men, there have been conflicting findings of the effect of the disease on sexual desire. Some studies have found that diabetic men have shown lower levels of sexual desire than healthy, age-matched counterparts. While other researchers have found no difference in level of sexual desire between diabetic men and healthy controls. High-blood pressure has also been found to be related to declining levels of sexual desire in men and women alike.
Certain medications can cause changes in the level of experienced sexual desire through “non-specific effects on general well-being, energy level, and mood”. Declining levels of sexual desire have been linked to the use of anti-hypertension medication and many psychiatric medications; such as anti-psychotic medications, tricyclic anti-depressants, monoamine-oxidase (MAO) inhibitors, and sedative drugs. However, the most severe decreases in sexual desire relating to psychiatric medication occur due to the use of selective serotonin reuptake inhibitors (SSRIs). In women specifically, the use of anticoagulants, cardiovascular medications, medications to control cholesterol, and medications for hypertension contributed to low levels of desire. However, in men, only the use of anticoagulants and medications for hypertension was related to low levels of desire. In addition to the specific type of medication being used, the amount of medications used regularly was also found to be correlated with a lowering of sexual desire. One medication that many do not realize can lower sexual desire in women is the oral contraceptive. Not every woman experiences the negative side effects of the Pill, however, as many as one in four do. Oral contraceptives have been known to increase the levels of sex hormone-binding globulin (SHBG) in the body. In turn, high SHBG levels have been associated with a decline in sexual desire. Though it is not used as medication, the drug methamphetamine has a strong positive effect on many aspects of sexual behaviour, including sexual desire.
Sexual desire is said to be influenced by androgens in men and by androgens and estrogens in women. Many studies associate the sex hormone, testosterone with sexual desire. Testosterone is mainly synthesized in the testes in men and in the ovaries in women. Another hormone thought to influence sexual desire is oxytocin. Exogenous administration of moderate amounts of oxytocin has been found to stimulate females to desire and seek out sexual activity. In women, oxytocin levels are at their highest during sexual activity.
- Regan, P.C.; Atkins, L. (2006). "Sex Differences and Similarities in Frequency and Intensity of Sexual Desire". Social Behavior & Personality: An International Journal 34 (1): 95–101.
- Spector, I. P.; Carey, M. P.; Steinberg, L. (1996). "The sexual desire inventory: Development, factor structure, and evidence of reliability". Journal of Sex & Marital Therapy 22 (3): 175. doi:10.1080/00926239608414655.
- Beck, J.G.; Bozman, A.W.; Qualtrough, T. (1991). "The Experience of Sexual Desire: Psychological Correlates in a College Sample". The Journal of Sex Research 28 (3): 443–456.
- Toates, F. (2009). "An Integrative Theoretical Framework for Understanding Sexual Motivation, Arousal, and Behavior". Journal of Sex Research 46 (2–3): 168–193. doi:10.1080/00224490902747768. PMID 19308842.
- Bacon, D. (2013, June 26). New models for sexual tension. Retrieved from http://www.themodernman.com/new-models-for-sexual-tension.html
- Basson, R. (2000). "The Female Sexual Response: A Different Model". Journal of Sex & Marital Therapy 26: 51–65. doi:10.1080/009262300278641. PMID 10693116.
- Levine, S. B. (2003). "The nature of sexual desire: A clinician's perspective". Archives of Sexual Behavior 32 (3): 279–285. doi:10.1023/A:1023421819465. PMID 12807300.
- Gonzaga, G. C.; Turner, R. A.; Keltner, D.; Campos, B.; Altemus, M. (2006). "Romantic Love and Sexual Desire in Close Relationships". Emotion 6 (2): 163–179. doi:10.1037/1528-35126.96.36.199. PMID 16768550.
- DeLamater, J.D.; Sill, M. (2005). "Sexual Desire in Later Life". The Journal of Sex Research 42 (2): 138–149.
- Tolman, D.L.; Diamond, L.M. (2001). "Desegregating Sexuality Research: Cultural and Biological Perspectives on Gender and Desire". Annual Review of Sex Research 12 (33): 33–75.
- Gagnon, John H (2004). An Interpretation of Desire. Chicago: University of Chicago.
- Baumeister, R. F.; Catanese, K. R.; Vohs, K. D. (2001). "Is There a Gender Difference in Strength of Sex Drive? Theoretical Views, Conceptual Distinctions, and a Review of Relevant Evidence". Personality and Social Psychology Review 5 (3): 242. doi:10.1207/S15327957PSPR0503_5.
- Masters, W.; Johnson, V.E. (2010). Human Sexual Response. Ishi Press International. p. 386. ISBN 9780923891213.
- James Giles (2008). The Nature of Sexual Desire. Lanham, Maryland: University Press of America ISBN 9780761840411
- Giles, J. (2006). "Social Constructionism and Sexual Desire". Journal for the Theory of Social Behaviour 36 (3): 225–238. doi:10.1111/j.1468-5914.2006.00305.x.
- Giles, J. (2008). "Sex Hormones and Sexual Desire". Journal for the Theory of Social Behaviour 38: 45. doi:10.1111/j.1468-5914.2008.00356.x.
- James Giles (2008). The Nature of Sexual Desire. Lanham, Maryland: University Press of America ISBN 9780761840411
- Baumeister, R. F. (2004). "Gender and erotic plasticity: Sociocultural influences on the sex drive". Sexual and Relationship Therapy 19 (2): 133–139. doi:10.1080/14681990410001691343.
- Ostovich, J. M.; Sabini, J. (2004). "How are Sociosexuality, Sex Drive, and Lifetime Number of Sexual Partners Related?". Personality and Social Psychology Bulletin 30 (10): 1255–1266. doi:10.1177/0146167204264754. PMID 15466599.
- Lippa, R. A. (2007). "Sex Differences in Sex Drive, Sociosexuality, and Height across 53 Nations: Testing Evolutionary and Social Structural Theories". Archives of Sexual Behavior 38 (5): 631–651. doi:10.1007/s10508-007-9242-8. PMID 17975724.
- Conaglen, H. M.; Evans, I. M. (2006). "Pictorial Cues and Sexual Desire: An Experimental Approach". Archives of Sexual Behavior 35 (2): 197. doi:10.1007/s10508-005-9000-8.
- Basson, R. (2002). "A Model of Women's Sexual Arousal". Journal of Sex & Marital Therapy 28: 1–0. doi:10.1080/009262302317250963.
- Diamond, L. M. (2003). "What does sexual orientation orient? A biobehavioral model distinguishing romantic love and sexual desire". Psychological Review 110 (1): 173–192. doi:10.1037/0033-295X.110.1.173. PMID 12529061.
- Brotto, L. A. (2009). "The DSM Diagnostic Criteria for Hypoactive Sexual Desire Disorder in Women". Archives of Sexual Behavior 39 (2): 221–239. doi:10.1007/s10508-009-9543-1. PMID 19777334.
- Sills, T.; Wunderlich, G.; Pyke, R.; Segraves, R. T.; Leiblum, S.; Clayton, A.; Cotton, D.; Evans, K. (2005). "The Sexual Interest and Desire Inventory-Female (SIDI-F): Item Response Analyses of Data from Women Diagnosed with Hypoactive Sexual Desire Disorder". The Journal of Sexual Medicine 2 (6): 801–818. doi:10.1111/j.1743-6109.2005.00146.x. PMID 16422805.
- Clayton, A. H.; Segraves, R. T.; Leiblum, S.; Basson, R.; Pyke, R.; Cotton, D.; Lewis-d'Agostino, D.; Evans, K. R.; Sills, T. L.; Wunderlich, G. R. (2006). "Reliability and Validity of the Sexual Interest and Desire Inventory–Female (SIDI-F), a Scale Designed to Measure Severity of Female Hypoactive Sexual Desire Disorder". Journal of Sex & Marital Therapy 32 (2): 115. doi:10.1080/00926230500442300.
- American Psychiatric Association (2000). Diagnostic and Statistical Manual of Mental Disorders. Washington, DC: American Psychiatric Publishing. ISBN 978-0890420256.
- Brotto, L. A.; Petkau, A. J.; Labrie, F.; Basson, R. (2011). "Predictors of Sexual Desire Disorders in Women". The Journal of Sexual Medicine 8 (3): 742–753. doi:10.1111/j.1743-6109.2010.02146.x. PMID 21143419.
- Basson, R.; Leiblum, S.; Brotto, L.; Derogatis, L.; Fourcroy, J.; Fugl-Meyer, K.; Graziottin, A.; Heiman, J. R.; Laan, E.; Meston, C.; Schover, L.; Van Lankveld, J.; Schultz, W. W. (2003). "Definitions of women's sexual dysfunction reconsidered: Advocating expansion and revision". Journal of Psychosomatic Obstetrics & Gynecology 24 (4): 221. doi:10.3109/01674820309074686.
- Brotto, L. A. (2009). "The DSM Diagnostic Criteria for Sexual Aversion Disorder". Archives of Sexual Behavior 39 (2): 271–277. doi:10.1007/s10508-009-9534-2. PMID 19784769.
- Montgomery, K.A. (2008). "Sexual Desire Disorders". Psychiatry (Edgmont) 5 (6): 50–55.
- , DSM-5 Website
- Delamater, J. (2012). "Sexual Expression in Later Life: A Review and Synthesis". Journal of Sex Research 49 (2–3): 125–141. doi:10.1080/00224499.2011.603168. PMID 22380585.
- Schiavi, R. C.; Stimmel, B. B.; Mandeli, J.; Rayfield, E. J. (1993). "Diabetes, sleep disorders, and male sexual function". Biological Psychiatry 34 (3): 171–177. doi:10.1016/0006-3223(93)90388-T. PMID 8399810.
- Samuels, N. (2010). "The Irony of Oral Contraceptives". The Womens Health Activist 35 (4): 8–9.