4.7: Masters and Johnson's Research
In 1966, William Masters and Virginia Johnson published a book detailing the results of their observations of nearly 700 people who agreed to participate in their study of physiological responses during sexual behavior. Unlike Kinsey, who used personal interviews and surveys to collect data, Masters and Johnson observed people having intercourse in a variety of positions, and they observed people masturbating, manually or with the aid of a device. While this was occurring, researchers recorded measurements of physiological variables, such as blood pressure and respiration rate, as well as measurements of sexual arousal, such as vaginal lubrication and penile tumescence (swelling associated with an erection). In total, Masters and Johnson observed nearly 10,000 sexual acts as a part of their research (Hock, 2008).
Based on these observations, Masters and Johnson divided the sexual response cycle into four phases that are fairly similar regardless of biological sex: excitement, plateau, orgasm, and resolution. The excitement phase is the arousal phase of the sexual response cycle, and it is marked by erection of the penis or clitoris, and lubrication and expansion of the vaginal canal. During plateau, further swelling of the vulva and increased blood flow to the labia minora takes place, and full erection of the penis with possible excretion of pre-ejaculatory fluid. Everyone in the study experienced increases in muscle tone during this time. Orgasm is marked in people with vulvas by rhythmic contractions of the pelvis and uterus, along with increased muscle tension. In people with penises, pelvic contractions are accompanied by a buildup of seminal fluid near the urethra that is ultimately forced out by contractions of genital muscles, (i.e., ejaculation). Resolution is the relatively rapid return to an unaroused state accompanied by a decrease in blood pressure and muscular relaxation. While many people with vulvas can quickly repeat the sexual response cycle, people with penises must pass through a longer refractory period as part of resolution. The refractory period is a period of time that follows an orgasm during which an individual is incapable of experiencing another orgasm. In people with penises, the duration of the refractory period can vary dramatically from individual to individual, with some refractory periods as short as several minutes and others as long as a day. As people with penises age, their refractory periods tend to span longer periods of time. In addition to the insights that their research provided with regards to the sexual response cycle and the multi-orgasmic potential of people with vulvas, Masters and Johnson also collected important information about reproductive anatomy. Their research demonstrated the oft-cited statistic of the average size of a flaccid and an erect penis (3 and 6 inches, respectively), as well as dispelling long-held beliefs about relationships between the size of an erect penis and the ability to provide sexual pleasure to a partner. Furthermore, they determined that the vulva is a very elastic structure that can conform to penises of various sizes (Hock, 2008).
The preceding two sections are adapted from Psychology . By: OpenStax College. Located at: http://cnx.org/contents/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:1/Psychology . CC BY: Attribution .
Mirror activity during arousal
Oh what amazing things our bodies do! Here’s an activity to demonstrate just that and have some fun at the same time. Have you ever wondered what your genitals do as you orgasm? Maybe you know, maybe you don’t. Probably what you’ve seen in porn isn’t anatomically accurate so why not see for yourself. The mirror exercise we did at the beginning of the class is now being revisited but this time try watching yourself as you masturbate. This might be logistically harder based on what your hands are doing, but give it a try. Observe firsthand how you physically react during climax. Have fun!