Sexual desire motivates humans and other animals to seek out sexual objects or partners with whom to engage in sexual activities. Sexual desire can also be called lust, sexual attraction, sexual motivation, libido, or sex drive. Individual sexual desires and behaviors are shaped by many factors. Substantial evidence indicates sexual desire in men and women is correlated with levels of the hormone testosterone. Other factors that shape sexual behavior include age, sex, previous experiences, values, social norms, and cultural expectations.
In 1947 American biologist Alfred Kinsey initiated a large-scale survey to research sexual behavior in men and women. Kinsey's research revealed information that was relatively surprising at the time. For example, results indicated that like men, many women were interested in sex and were sexually experienced. People had engaged in a wide variety of sexual practices, both inside and outside committed relationships. Homosexual behaviors were relatively common. Both men and women masturbated, even when they also had sexual partners. Masturbation did not cause negative health consequences.
Kinsey's research has been widely criticized for its sampling and statistical errors. For example, findings in his book Sexual Behavior in the Human Male were drawn from a sample of respondents that included no African Americans. Kinsey's sample also included disproportionately high numbers of prison inmates, college students, and men recruited through organizations that supported homosexuality. Critics pointed out that his sample did not represent the American population in general. Despite limitations, his research paved the way for future human sexuality research.
Human Sexual Response
The human sexual response cycle is a four-part model of physiological responses to sexual stimulation. This model was developed in 1966 based on observations by American gynecologist William Masters and American sexologist Virginia Johnson. The two had begun collaborating at the University of Washington at St. Louis before opening the Reproductive Biology Research Foundation in St. Louis in 1964. Masters and Johnson divided the cycle into four phases: excitement, plateau, orgasm, and resolution.
The excitement phase is when initial arousal occurs. In men, the penis becomes erect. In women, the clitoris swells, and the vaginal canal becomes lubricated and expands. During the plateau phase, muscle tone and blood flow increase, causing further swelling of the vagina in women and a full erection with pre-ejaculatory fluid in men. Muscle tension increases during the orgasm phase. Women experience rhythmic contractions of the pelvis and uterus and can have multiple orgasms during one sexual response cycle. Men experience pelvic contractions and a buildup of seminal fluid near the urethra, which is forced out by a single ejaculation. The resolution phase is a rapid return to an unaroused state, including muscular relaxation and a decrease in blood pressure.
This cycle applies to both men and women, although men may progress more rapidly to orgasm. There are multiple pathways through this cycle. The duration of each phase can differ across individuals and sexual encounters. For example, the plateau phase may be short or long, and the response cycle is not necessarily completed during every sexual encounter. That is, excitement does not lead inevitably to orgasm.The refractory period is the time during which an individual cannot physically experience another orgasm. This period occurs after orgasm and during resolution. Many women can quickly repeat the sexual response cycle with little to no refractory period. For men, the refractory period can range from several minutes to a full day. The amount of time a man has to wait varies between individuals and usually grows longer with age.
Arousal Levels during the Four Stages of Sexual Response
Sex, Gender, and Sexual Orientation
The terms sex and gender are often confused. Sex refers to the chromosomes, hormones, and sexual anatomy that differ between males, females, and people who are intersex. People who are intersex have physical characteristics that are not considered typically male or female. They may have chromosomes (DNA molecules containing genetic material), hormones, or sexual anatomy that is not clearly male or female. About 1 in 100 people are born with bodies that differ from the standard male or female body in some way.
Gender refers to the attitudes, interests, behaviors, and activities a culture associates with being biologically male or female. Psychologists agree that sex is biological while gender is a societal construct.
Gender roles are cultural expectations about how men and women should think, feel, and act. Historically, many societies have had a relatively narrow set of ideas about gender roles. They dictate everything from how a person is expected to dress to how they should express emotion. These expectations are at least partially culturally constructed; gender stereotypes differ around the world and over time. However, many elements of gender roles in the United States are common around the world. Both male and female gender role stereotypes can put unwanted limits on a person's self-expression.
Gender Role Stereotypes
|Male Gender Role Stereotypes||Female Gender Role Stereotypes|
Stoic and unemotional
Gender identity is the sense of oneself as male, female, or being elsewhere on the gender spectrum. Transgender means having a gender identity that does not match one's assigned birth sex. Behaviors that are compatible with cultural expectations are referred to as gender-normative. Behaviors that are incompatible with cultural expectations are considered gender nonconforming.
While gender options beyond male and female constitute a relatively modern concept in the United States, some other cultures have recognized additional gender options for centuries. In Thailand, people can identify as male, female, or kathoey. The term kathoey has been used to describe a range of individuals including transgender woman, intersex individuals born with sexual anatomy that blends typical male and female elements, and effeminate gay men.
Sexual orientation is an individual's emotional and erotic attractions toward another individual. A person's sexual orientation often falls into one of the following categories:
- heterosexual: having emotional and erotic attractions toward individuals of the opposite sex
- homosexual: having emotional and erotic attractions toward individuals of the same sex
- bisexual: having emotional and erotic attractions toward individuals of the opposite sex and individuals of the same sex
- asexual: having limited erotic desire
Sexual orientation does not always fit neatly into one of these four categories. Kinsey proposed that sexual orientation occurs on a continuum. He developed the Kinsey scale, which allowed people to place themselves on a continuum from strongly heterosexual to strongly homosexual. Individuals may be primarily heterosexual (at one end of the scale), primarily homosexual (at the opposite end), bisexual (in the middle), or some other proportion of hetero-/homosexual.
There are many false, but common, myths about sexual orientation. One myth states homosexuality and bisexuality are related to poor parenting abilities or sexual abuse during childhood. Another myth is that most people choose their sexual orientation. In reality, most people experience sexual orientation as innate; they are born with it. There are many biological determinants of sexual orientation, including genes, brain structure, and the prenatal environment.
Another myth claims conversion therapy is successful in turning homosexual people heterosexual. In a 1979 book, American sex researchers William Masters and Virginia Johnson claimed to have converted people unhappy with their same-sex desires or behaviors into heterosexuals. Since then, attempts at conversion therapy have included hormone treatments, administering nausea-inducing medications or electric shocks to people viewing erotic material, counseling, and visualization. After decades of research, no credible scientific evidence suggests individuals can change their sexual orientation. Conversation therapy has been linked to increased shame, guilt, depression, and anxiety. Because the therapy does not change sexual orientation and does increase distress, many states have made conversion therapy illegal.