Nipple stimulation or breast stimulation is stimulation of the breast. Stimulation may be by breastfeeding, sexual activity, or an indirect non-sexual response. As part of sexual activity, the practice may be performed upon, or by, people of any gender or sexual orientation. It may occur with the use of fingers, orally, such as by sucking or licking, as well as by use of an object. Nipple stimulation may produce sexual excitement, and erect nipples can be an indicator of an individual's sexual arousal. Adult women and men report that breast stimulation may be used to both initiate and enhance sexual arousal, and a few women report experiencing orgasm from nipple stimulation.
Development and anatomy
Male and female breasts, nipples and areolasdevelop similarly in the fetus and during infancy. At puberty, the male's breasts remain rudimentary but the female's develop further, mainly due to the presence of estrogen and progesterone, and become much more sensitive than the male ones. Smaller female breasts, however, are more sensitive than larger ones.
Physiological response
Breasts, and especially the nipples, are erogenous zones. Nipple stimulation may result in sexual arousal, and erect nipples can be an indicator of an individual's sexual arousal. The individual's sexual partner may find such erection erotically stimulating. A survey in 2006 found that sexual arousal in about 82% of young females and 52% of young males occurs or is enhanced by direct stimulation of nipples, with only 7–8% reporting that it decreased their arousal. The stimulation of women's nipples from suckling, including breastfeeding, promotes the production and release of oxytocin and prolactin. Besides creating maternal feelings, it also decreases a woman's anxiety and increases feelings of bonding and trust. Oxytocin is linked to sexual arousal and pair bonding, but researchers are divided on whether breastfeeding commonly incites sexual feelings. Nipple erection during sexual arousal or breastfeeding are both caused by the release of oxytocin. Nipple erection is due to the contraction of smooth muscle under the control of the autonomic nervous system, and is a product of the pilomotor reflex which causes goose bumps. Few women report experiencing orgasm from nipple stimulation. Before Komisaruk et al.'s functional magnetic resonance research on nipple stimulation in 2011, reports of women achieving orgasm from nipple stimulation relied solely on anecdotal evidence. Komisaruk's study was the first to map the female genitals onto the sensory portion of the brain; it indicates that sensation from the nipples travels to the same part of the brain as sensations from the vagina, clitoris and cervix, and that these reported orgasms are genital orgasms caused by nipple stimulation, and may be directly linked to the genital sensory cortex.
