Human penis size varies on a number of measures, including length and circumference when Flaccid penis and erect penis. Besides the natural variability of in general, there are factors that lead to minor variations in a particular male, such as the level of sexual arousal, time of day, ambient temperature, anxiety level, physical activity, and frequency of sexual activity. Compared to other , including large examples such as the gorilla, the human penis is thickest, both in absolute terms and relative to the rest of the body. Most human penis growth occurs in two stages: the first between infancy and the age of five; and then between about one year after the onset of puberty and, at the latest, approximately 17 years of age.
Measurements vary, with studies that rely on self-measurement reporting a significantly higher average than those with a health professional measuring. A 2015 systematic review measured by health professionals rather than self-reporting, found an average erect length of , and average erect circumference of . A 1996 study of flaccid length found a mean of when measured by staff. Flaccid penis length can sometimes be a poor predictor of erect length. An adult penis that is abnormally small but otherwise normally formed is referred to in medicine as a micropenis.
Limited to no statistically significant correlation between penis size and the size of other body parts has been found in research. Some environmental factors in addition to genetics, such as the presence of endocrine disruptors, can affect penis growth.
The 2015 review (measured by staff) found average flaccid, stretched, and erect lengths of , , and , respectively, and average flaccid and erect circumferences of and , respectively. Erect length in the studies was measured by pushing the pre-pubic fat pad to the bone, and flaccid or erect girth (circumference) was measured at the base or mid-shaft of the penis.
The penis and scrotum can contract involuntarily in reaction to cold temperatures, anxious or nervous level and participation in sports. This decrease of flaccid penis size is referred to by the slang term "shrinkage", due to action by the cremaster muscle. The same phenomenon affects cyclists and exercise bike users, with prolonged pressure on the perineum from the bicycle saddle and the straining of the exercise causing the penis and scrotum to contract involuntarily. An incorrect saddle may ultimately cause erectile dysfunction (see crotch pressure for more information). Individuals with hard flaccid syndrome or other pelvic floor disorders may temporarily have an abnormally small penis.
A 2020 review found most men believed the average erect penis length is more than 15.24 cm (6 inches). This inaccurate belief has likely been fed by inaccurate and exaggerated data presented in studies where the size of a participant's erect penis is self-reported. Participants may report overestimates of the size of their penis in the belief that a larger penis is more socially desirable. The same review analyzed the results from ten prior studies where measurements of erect penis size were made by researchers. They reported an erect penis to be between 12.95 and 13.92 cm (5.1 and 5.5 inches, respectively) in length, a result significantly below the average obtained in self-reported studies. The authors commented that results of such measurement studies may still be inflated due to volunteer bias — the possibility that men with larger penises may be more likely to choose to participate in such studies.
W.A. Schonfeld published a penis growth curve in 1943.
Nose size was highly related to stretched penile length in Japanese male cadavers.
There may be a link between the malformation of the genitalia and the human limbs. The development of the penis in an embryo is controlled by some of the same (in particular HOXA13 and HOXD13) as those that control the development of the limbs. Mutations of some Hox genes that control the growth of limbs cause malformed genitalia (hand-foot-genital syndrome).
According to urologist Aaron Spitz, many websites and studies promoting variation of penis size between races use Pseudoscience of collecting information and often ignore contradictory evidence. He concludes that "when you really take a good look at the naked data, there's not a whole lot there showing."
A small study of 50 undergraduate women, surveyed by two popular male athletes on campus about their perceptions of sexual satisfaction; found the width of a penis feels better than the length of a penis, when subjects are asked to choose between the two (size was left unspecified). It was also concluded that this may show that penis size overall affects sexual satisfaction, since women chose between the two options they were given.
A 2002 study at Groningen University Hospital, asked 375 sexually active women (who had recently given birth) the importance of penis size. The results showed that 21% of women felt length was important and 32% felt that girth was important.
A 2013 study conducted at the Australian National University, showed that penis size influences a man's sex appeal, and the taller the man, the bigger the effect. The study showed life-sized 3D computer-generated images, altering the height and other physical attributes, with women typically registering preferences in under 3 seconds. A preference for taller men's larger penis size was indicated.
A 2015 US study of the stated preferences of 75 women using 3D-printed models as references showed a preferred penis length of and a preferred circumference of for long-term sexual partners, with slightly larger preferred sizes of a length of and circumference of for one-time sexual encounters.
According to the study, however, when estimating the length of their partner's penis, most women would say a size significantly smaller than what their partner was recorded to be. This suggests that perception of size is not entirely accurate. The visual impression of the size is not necessarily in correlation with the feeling in the vulva and vagina. A very long penis can cause dyspareunia, if the man doesn't understand how to use it carefully.
Both PCBs and the plasticizer DEHP have been associated with smaller penis size. DEHP metabolites measured from the urine of pregnant women have been significantly associated with the decreased penis width, shorter anogenital distance and the incomplete descent of of their newborn sons, replicating effects identified in animals. According to a 2008 study published by the US National Library of Medicine, approximately 25% of US women have phthalate levels similar to those observed in animals.
Penile size may decrease as a result of some hormonal therapy combined with external beam radiation therapy. In addition, some estrogen-based fertility drugs like diethylstilbestrol (DES) have been linked to genital abnormalities or a smaller than normal penis (microphallus).
Actors portraying male characters in ancient Greek comedy wore enormous, fake, red penises, which dangled underneath their costumes; these were intended as ridiculous and were meant to be laughed at.
In Aristophanes's comedy The Clouds, "Mr. Good Reason" gives the character Pheidippides a description of the ideal youth: "A glistening chest and glowing skin / Broad shoulders, a small tongue /A mighty bottom and a tiny prong."
In Greek mythology, Priapus, the god of fertility, had an impossibly large penis that was Priapism. Priapus was widely seen as hideous and unattractive. A scholia on Apollonius of Rhodes's Argonautica states that when Priapus' mother Aphrodite, the goddess of love and beauty, gave birth to him, she was so horrified by the size of his penis, his massive potbelly, and his huge tongue that she abandoned him to die in the wilderness. A herdsman found him and raised him as his son, later discovering that Priapus could use his massive penis to aid in the growth of plants.
Nonetheless, there are indications that the Greeks had an open mind about large penises. A statue of the god Hermes with an exaggerated penis stood outside the main gate of Classical Athens and in Alexandria in 275 BC, a procession in honor of Dionysus hauled a 180-foot phallus through the city and people venerated it by singing hymns and reciting poems. The Romans, in contrast to the Greeks, seem to have admired large penises and many large phalli have been recovered from the ruins of Pompeii. Depictions of Priapus were very popular in Roman erotic art and literature. Over Priapeia have survived.
Penis size is alluded to in the Bible:
Ancient Chinese legend holds that a man named Lao Ai had the largest penis in history and that he had an affair with Queen Dowager Zhao ( 280–228 BC), the mother of Qin Shi Huang, by pretending to be a eunuch. admired large penises and King Jijeung (437–514 AD) of the Silla Dynasty is said to have had a forty-five-centimeter penis that was so large his subordinates had to search for a woman that fit him. Traditional erotic paintings usually show genitals as exaggeratedly large. The oldest known painting of this type, found in the Hōryū-ji Temple in Ikaruga, dates to the eighth century AD and depicts a fairly large penis.
The ancient Indian sexual treatise Kama Sutra, written in Sanskrit, probably between the second and fourth centuries AD, divides men into three classes based on penis size: "hare" size (about 5–7 cm, or 2–3 inches, when erect), "bull" size (10–15 cm, or 4–6 inches), and "horse" size (18–20 cm, or 7–8 inches). The treatise also divides women's vaginas into three sizes ("deer", "mare", and "elephant") and advises that a man match the size of the vagina of the woman he is having sex with to the size of his own penis. It also gives medically dubious advice on how to enlarge one's penis using .
The medieval Norsemen considered the size of a man's penis as the measure of his manliness, and a thirteenth-century Norse magic talisman from Bergen, a wooden stave inscribed in runic script, promises its wearer: "You will fuck Rannveig the Red. It will be bigger than a man's prick and smaller than a horse's prick." A late fourteenth century account of the life of Saint Óláfr from the Flateyjarbók describes a pagan ritual which centered around a preserved horse's penis used as a cult artifact which members of the cult would pass around in a circle, making up verses in praise of it, encouraging it and the other members of the group to behave in sexually suggestive ways.
During the Renaissance, some men in Europe began to wear , which accentuated their genitals. There is no direct evidence that it was worn to enhance the apparent size of the wearer's penis, but larger codpieces were seen as more fashionable.
Small penis syndrome (SPS), a term sometimes used in medical literature, is characterized by an obsessive concern that the penis is smaller than average, often despite normal measurements. It has been associated with wider psychological disorders, including anxiety and body Dysmorphopsia disorder. Assessment focuses on confirming normality and addressing underlying psychological factors.
The evolutionary reasons for the increased thickness have not been established. One explanation is that thicker penises are an adaptation to a corresponding increase in vaginal size. The vaginal canal is believed to have expanded in humans to accommodate the larger size of a newborn's skull. Women may then have Sexual selection men with penises large enough to fit their vagina, to provide sexual stimulation and ensure ejaculation.
Other evolutionary hypotheses to explain humans' relatively large penis length and girth include a sperm competition hypothesis and a mate competition hypothesis. The sperm competition hypothesis does not have much support as in other mammals where sperm competition is present, larger testes evolve, not larger penises. The mate competition hypothesis involves the prediction that a human with a larger penis would be able to displace the sperm of another. Studies have found that larger penises do not displace other sperm more effectively than smaller penises, but rather longer penises may ejaculate sperm inside the vagina in places that would be harder for a following penis to displace. The depth of pelvic thrusting was correlated to the displacement of competing sperm.
Length
Flaccid
Stretched
Erect
Erect circumference
Size at birth and during childhood
Size in older men
Size and height
Size and hands
Size and other body parts
Size, race, and ethnicity
Size preferences among sexual partners
Condom use
Biochemistry
Variance
Genetics
Conditions
Environmental influence
Historical perceptions
Ancient
18 And she revealed her whorings, and she revealed her nakedness, and so I turned from her just as I turned from her sister. 19 Yet she increased her whorings, recalling the days of her childhood when she was prostituted in the land of Egypt. 20 And she lusted after her male lovers whose genitalia were the genitalia of male donkeys and their seminal emission was the seminal emission of horses. Ezekiel 23:18–20 Lexham English Bible
Post-classical
Contemporary perceptions
Male self-perception
Shrinking and enlarging
Among male homosexuals
Pornography, black men, and penis size
Evolution
See also
Citations
General and cited sources
External links
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