Sexual desire, or libido, is an intense sexual feeling that a person has for another person. Many factors contribute to sexual desire, including physical stimuli and biological conditions like genes and hormones. Libido levels can vary greatly between individual people, and between men and women, leading many researchers to emphasize that there is no “normal” level of sexual desire.
Modern study of sexual desire began primarily with Sigmund Freud (1856-1939), who believed that sexual desire, which he termed libido, is a person’s primary motivation. Freud theorized that libido develops over each stage in life, and that our psychological and emotional health as an adult is directly related to the sexual experiences we had as infants. Today, psychologists believe libido is a combination of hormones and physical pleasure (such as stimulating certain nerve endings), which is shaped and molded by outside social influences such as cultural norms.
Hormones like testosterone and estrogen play a major role in sexual desire. Testosterone is produced in both men and women, though men typically produce 20 times the amount of testosterone as women do. In men, testosterone causes muscle buildup and facial hair as well as increased libido and aggression. Estrogen, on the other hand, is produced in significantly higher levels by women, though researchers believe that men who completely lack estrogen may have extremely low libido.
A number of different stimuli can trigger sexual desire. Internal stimuli can include feelings of intimacy and erotic thoughts and fantasies. External stimuli can include things like smells and food. The aromas of lavender, licorice and almonds have been shown to increase sexual desire, and a recent study found that for women, smells associated with breastfeeding increase libido. Eating chocolate can also give libido a boost because it contains phenylethylalamine, the same chemical that releases euphoric sensations in our brains when we first fall in love.
Sexual desire can be driven by both physical and psychological factors. Physical factors include biological chemicals (hormones) as well as dopamine D4 receptor, a gene that partly controls the brain’s pleasure system. Psychological factors can include mental urges, like the desire for companionship, emotional intimacy, power or even the desire to have children. And while there is an important connection between the psychological feeling of romantic love, studies have shown that sexual desire and romantic love are two separate phenomena.
The type and amount of sexual desire can vary depending on gender, ethnicity and cultural influences. According to a 2006 study entitled “Sex Differences and Similarities in Frequency and Intensity of Sexual Desire” by Pamela Regan and Leah Atkins at California State University, men experience sexual desire approximately four times as frequently as women. A 2003 study found that European American, African-American, and Hispanic American women reported higher levels of sexual desire than did Chinese-American and Japanese-American women. Sociologists have also found that a culture’s sexual taboos often dampen or, ironically, fuel certain types of sexual desire.