Human penis size
Encyclopedia
Human penis size is the measured length and width of the human
penis
. The most accurate measurement of the human penis comes from several measurements at different times, as there is natural variability in size due to arousal level, time of day, room temperature, frequency of sexual activity, and unreliability of the measurement methods. When compared to other primates, including large primate
s such as the gorilla, the genitalia of male humans are large, both in absolute terms and in relative size to the rest of the body. Results vary, with studies that rely on self-measurement reporting a significantly higher average than those with staff measuring, but a mean
erect human penis is approximately 12.9–15.0 cm (5.1–5.9 in
) in length. Flaccid penis length is a poor estimate of erect
length. Most of human penis growth happens between infancy and the age of five, and in five years after the onset of puberty
.
There is evidence both for and against a link between penis size and the size of other body parts. Some environmental factors in addition to genetic, such as the presence of endocrine disruptor
s, can affect penis growth. An adult penis with an erect length of less than 7 cm or just over 2 inches but otherwise formed normally is referred to in a medical context as having the micropenis
condition. Circumcised men are on average 8 millimeters shorter in terms of erect length compared to their intact counterparts.
and in Renaissance
art, an uncircumcised
and small penis was culturally seen as desirable in a man, whereas a bigger or circumcised
penis was viewed as comical or grotesque. Ancient Rome
may have had a contrary view, and a larger penis size was preferred in medieval Arabic literature
. Males may quite easily underestimate the size of their own penis relative to that of others, and many men who believe that their penis is of inadequate size have average-sized penises. The perception of having a large penis is often linked to higher self esteem. For women, width rather than length is a more important factor of sexual stimulation. Fear of shrinking of the penis in folklore have led to a type of mass hysteria called penis panic
, though the penis legitimately can shrink in size due to scar tissue formation in the penis from a medical condition called Peyronie's disease
. Marketers of penis enlargement
products exploit fears of inadequacy, but there is no consensus in the scientific community of any non-surgical technique that permanently increases either the thickness or length of the erect penis that already falls into the normal range.
human penis is approximately 12.9–15 cm (5.1–5.9 in) in length with a 95% confidence interval
of (10.7 cm, 19.1 cm) (or, equivalently, 4.23 in, 7.53 in).
The consensus on typical circumference
is 12.3 cm (4.85 in), requiring a diameter of roughly 3.9 cm (1.54 in) when fully erect
.
Another reputable source claims that the relaxed (flaccid, non-tumescent) human penis has an average length of only 4 inches (≈10.2 cm) and a diameter of 1¼ inches (≈3.2 cm) (which would result in a circumference of roughly 3.9in/10.1 cm) while fully erect ones have an average length of 6 in (≈15.2 cm) and a diameter of 1½ inches (≈3.8 cm), resulting in an erect circumference of 4.71in/11.9 cm.
The mean penis size is slightly greater than the median
size. Studies have not found a relation between penis size and race. Circumcised men are on average 8 millimeters shorter in terms of erect length compared to their intact counterparts.
The average stretched penile length at birth is about 4 cm (1.6 in), and 90% of newborn boys will be between 2.4 and 5.5 cm (0.9 and 2.2 in). Limited growth of the penis occurs between birth and 5 years of age, but very little occurs between 5 years and the onset of puberty
. The average size at the beginning of puberty is 6 cm (2.4 in) with adult size reached about 5 years later. W.A. Schonfeld published a penis growth curve in 1943.
Age is not believed to negatively correlate with penis size. “Individual research studies have… suggested that penis size is smaller in studies focusing on older men, but Wylie and Eardley found no overall differences when they collated the results of various studies [over a 60 year period],” however, there is some evidence to suggest that testicle size is getting progressively smaller with younger cohorts.
length of the adult penis. Studies which have relied on self-measurement, including those from Internet surveys, consistently reported a higher average length than those which used medical or scientific methods to obtain measurements.
The following staff-measured studies are each composed of different subgroups of the human population (i.e. specific age range and/or race; selection of those with sexual medical concerns or self-selection
) which could cause a sample bias
.
Similar results exist regarding studies of the circumference
of the adult fully erect
penis, with the measurement taken mid-shaft. As with length, studies that relied on self-measurement consistently reported a significantly higher average than those with staff measuring.
The penis and scrotum can contract involuntarily in reaction to cold temperatures or nervousness, referred to by the slang term "shrinkage", due to action by the cremaster muscle
. The same phenomenon affects cyclist and exercise bike users, with prolonged pressure on the perineum from the 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).
Flaccid penis length is a poor estimate of erect length; a better estimate is stretched length, that is 12–13 cm, as shown in review by Wylie and Erdley.
condition. The condition affects 0.6% of men. Some of the identifiable causes are deficiency of pituitary growth hormone
and/or gonadotropin
s, mild degrees of androgen insensitivity
, a variety of genetic syndromes, and variations in certain Homeobox
genes. Some types of micropenis can be addressed with growth hormone or testosterone
treatment in early childhood. Operations are also available to increase penis size in cases of micropenis in adults.
, but also by environmental factors such as culture
, diet
, chemical/pollution exposure, etc. Endocrine disruptor
resulting from chemical exposure has been linked to genital deformation in both sexes (among many other problems). Chemicals from both synthetic (e.g. pesticides, anti-bacterial Triclosan
, plasticizers for plastics, etc...) and natural (e.g. chemicals found in tea tree oil and lavender oil) sources have been linked to various degrees of endocrine disruption. Both PCBs
and the plasticizer DEHP
have been associated with smaller penis size. DEHP metabolites measured from the blood of pregnant women have been significantly associated with the decreased penis width, shorter anogenital distance
, and the incomplete descent of testicle
s of their newborn sons, replicating effects identified in animals. Approximately 25% of US women have phthalate levels similar to those in the study. A 2007 study by University of Ankara, Faculty of Medicine has found that 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 and/or a smaller than normal penis (microphallus).
According to Kenneth Dover's landmark study "Greek Homosexuality", Greek art had extreme interest in the genitals, but was not obsessed with size. The weekly Q&A column "The Straight Dope" deduces, based on pornographic Greek art work and Dover's aforementioned study, that in ancient Greece
an uncircumcised and small penis was culturally seen as desirable in a man, whereas a bigger or circumcised penis was viewed as comical or grotesque, usually being found on "fertility gods, half-animal critters such as satyr
s, ugly old men, and barbarians."
CBC
radio has suggested, based on several sources, that ancient Romans
had a viewpoint contrary to that of the Greeks. This was also the case in medieval Arabic literature
, where a longer penis was preferred, as described in an Arabian Nights tale called "Ali with the Large Member". As a witty satire
of this fantasy, the 9th century Afro-Arab
author Al-Jahiz
wrote: "If the length of the penis were a sign of honor, then the mule
would belong to the (honorable tribe of) Quraysh".
Penis size is also alluded to in the Bible
:
data set found that homosexual men had statistically larger penises than their heterosexual counterparts. One potential explanation given is a difference in the exposure to androgen hormones in the developing embryo. Evidence points towards men of both orientations being equally likely to exaggerate the size of their penises.
sayings and popular culture
reflections related to penis size. Penis panic
is a form of mass hysteria involving the believed removal or shrinking of the penis, known as genital retraction syndrome
. The penis can significantly shrink due to scar tissue formation from a condition called Peyronie's disease
which affects up to 10% of men. Products such as penis pumps, pills, and other dubious means of penis enlargement
are some of the most marketed products in email spam. At present there is no consensus in the scientific community of any non-surgical technique that permanently increases either the thickness or length of the erect penis that already falls into the normal range (4.5" to 7").
A potential explanation for a link is that the development of the penis in an embryo is controlled by some of the same Hox genes (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
).
Similar results were found in a cover story published in Psychology Today
, which surveyed 1,500 readers (about 2/3 women) about male body image. Many of the women were not particularly concerned with penis size and over 71% thought men overemphasized the importance of penis size and shape. Generally, the women polled cared more about width than men thought, and less about length. "...the number one reason women preferred a thicker penis was that it was more satisfying during intercourse."
Another study, conducted at Groningen University Hospital, asked 375 sexually active women (who had recently given birth) the importance of penis size and concluded: "Although clearly in the minority, a nevertheless considerable percentage of the women respondents attached substantial importance to the size of the male sexual organ".
The term size queen is slang for a person who prefers their sexual partner(s) to have a larger-than-average penis.
s, including large primates such as the gorilla
, the genitalia of male humans are large. The human penis is both longer and thicker than that of any other primate, both in absolute terms and in relative size to the rest of the body.
(see Implications of differences in penis length and morphology for hypothesized advantages involving group sex which may have led to the evolution of a larger penis size in humans, and factors which may account for differences in average penis size within the human species).
Human
Humans are the only living species in the Homo genus...
penis
Penis
The penis is a biological feature of male animals including both vertebrates and invertebrates...
. The most accurate measurement of the human penis comes from several measurements at different times, as there is natural variability in size due to arousal level, time of day, room temperature, frequency of sexual activity, and unreliability of the measurement methods. When compared to other primates, including large primate
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s such as the gorilla, the genitalia of male humans are large, both in absolute terms and in relative size to the rest of the body. Results vary, with studies that rely on self-measurement reporting a significantly higher average than those with staff measuring, but a mean
Arithmetic mean
In mathematics and statistics, the arithmetic mean, often referred to as simply the mean or average when the context is clear, is a method to derive the central tendency of a sample space...
erect human penis is approximately 12.9–15.0 cm (5.1–5.9 in
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
) in length. Flaccid penis length is a poor estimate of erect
Erection
Penile erection is a physiological phenomenon where the penis becomes enlarged and firm. Penile erection is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal...
length. Most of human penis growth happens between infancy and the age of five, and in five years after the onset of puberty
Puberty
Puberty is the process of physical changes by which a child's body matures into an adult body capable of reproduction, as initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy...
.
There is evidence both for and against a link between penis size and the size of other body parts. Some environmental factors in addition to genetic, such as the presence of endocrine disruptor
Endocrine disruptor
Endocrine disruptors are chemicals that interfere with endocrine in animals, including humans. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders...
s, can affect penis growth. An adult penis with an erect length of less than 7 cm or just over 2 inches but otherwise formed normally is referred to in a medical context as having the micropenis
Micropenis
Micropenis is an unusually small penis. A common criterion is a dorsal erect penile length of at least 2.5 standard deviations smaller than the mean human penis size. The condition is usually recognized shortly after birth...
condition. Circumcised men are on average 8 millimeters shorter in terms of erect length compared to their intact counterparts.
History
Perceptions of penis size are culture-specific. In Ancient GreeceAncient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
and in Renaissance
Renaissance
The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...
art, an uncircumcised
Foreskin
In male human anatomy, the foreskin is a generally retractable double-layered fold of skin and mucous membrane that covers the glans penis and protects the urinary meatus when the penis is not erect...
and small penis was culturally seen as desirable in a man, whereas a bigger or circumcised
Circumcision
Male circumcision is the surgical removal of some or all of the foreskin from the penis. The word "circumcision" comes from Latin and ....
penis was viewed as comical or grotesque. Ancient Rome
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
may have had a contrary view, and a larger penis size was preferred in medieval Arabic literature
Arabic literature
Arabic literature is the writing produced, both prose and poetry, by writers in the Arabic language. The Arabic word used for literature is adab which is derived from a meaning of etiquette, and implies politeness, culture and enrichment....
. Males may quite easily underestimate the size of their own penis relative to that of others, and many men who believe that their penis is of inadequate size have average-sized penises. The perception of having a large penis is often linked to higher self esteem. For women, width rather than length is a more important factor of sexual stimulation. Fear of shrinking of the penis in folklore have led to a type of mass hysteria called penis panic
Penis panic
Koro is a culture-specific syndrome from Southeast Asia in which the patient has an overpowering belief that his penis is shrinking and will shortly disappear. Also known as shrinking penis, the syndrome is listed in the Diagnostic and Statistical Manual of Mental Disorders...
, though the penis legitimately can shrink in size due to scar tissue formation in the penis from a medical condition called Peyronie's disease
Peyronie's disease
Peyronie's Disease Peyronie's Disease Peyronie's Disease (also known as "Induratio penis plastica", or more recently Chronic Inflammation of the Tunica Albuginea (CITA), is a connective tissue disorder involving the growth of fibrous plaques in the soft tissue of the penis affecting up to 10% of men...
. Marketers of penis enlargement
Penis enlargement
Penis enlargement procedures are techniques alleged to make the human penis increase in girth, length, or hardness. Often, in the course of advertising fraudulent products, the distinction between temporary enlargement, i.e...
products exploit fears of inadequacy, but there is no consensus in the scientific community of any non-surgical technique that permanently increases either the thickness or length of the erect penis that already falls into the normal range.
Studies on penis size
While results vary across studies, the consensus is that the meanArithmetic mean
In mathematics and statistics, the arithmetic mean, often referred to as simply the mean or average when the context is clear, is a method to derive the central tendency of a sample space...
human penis is approximately 12.9–15 cm (5.1–5.9 in) in length with a 95% confidence interval
Confidence interval
In statistics, a confidence interval is a particular kind of interval estimate of a population parameter and is used to indicate the reliability of an estimate. It is an observed interval , in principle different from sample to sample, that frequently includes the parameter of interest, if the...
of (10.7 cm, 19.1 cm) (or, equivalently, 4.23 in, 7.53 in).
The consensus on typical circumference
Circumference
The circumference is the distance around a closed curve. Circumference is a special perimeter.-Circumference of a circle:The circumference of a circle is the length around it....
is 12.3 cm (4.85 in), requiring a diameter of roughly 3.9 cm (1.54 in) when fully erect
Erection
Penile erection is a physiological phenomenon where the penis becomes enlarged and firm. Penile erection is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal...
.
Another reputable source claims that the relaxed (flaccid, non-tumescent) human penis has an average length of only 4 inches (≈10.2 cm) and a diameter of 1¼ inches (≈3.2 cm) (which would result in a circumference of roughly 3.9in/10.1 cm) while fully erect ones have an average length of 6 in (≈15.2 cm) and a diameter of 1½ inches (≈3.8 cm), resulting in an erect circumference of 4.71in/11.9 cm.
The mean penis size is slightly greater than the median
Median
In probability theory and statistics, a median is described as the numerical value separating the higher half of a sample, a population, or a probability distribution, from the lower half. The median of a finite list of numbers can be found by arranging all the observations from lowest value to...
size. Studies have not found a relation between penis size and race. Circumcised men are on average 8 millimeters shorter in terms of erect length compared to their intact counterparts.
Size at birth
Puberty
Puberty is the process of physical changes by which a child's body matures into an adult body capable of reproduction, as initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy...
. The average size at the beginning of puberty is 6 cm (2.4 in) with adult size reached about 5 years later. W.A. Schonfeld published a penis growth curve in 1943.
Size with aging
Authors of a paper reviewing research on area of penis sizes conclude that "flaccid penile length is just under 4 cm at birth and changes very little until puberty, when there is marked growth."Age is not believed to negatively correlate with penis size. “Individual research studies have… suggested that penis size is smaller in studies focusing on older men, but Wylie and Eardley found no overall differences when they collated the results of various studies [over a 60 year period],” however, there is some evidence to suggest that testicle size is getting progressively smaller with younger cohorts.
Erect length
Several scientific studies have been performed on the erectErection
Penile erection is a physiological phenomenon where the penis becomes enlarged and firm. Penile erection is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal...
length of the adult penis. Studies which have relied on self-measurement, including those from Internet surveys, consistently reported a higher average length than those which used medical or scientific methods to obtain measurements.
The following staff-measured studies are each composed of different subgroups of the human population (i.e. specific age range and/or race; selection of those with sexual medical concerns or self-selection
Self-selection
In statistics, self-selection bias arises in any situation in which individuals select themselves into a group, causing a biased sample with nonprobability sampling...
) which could cause a sample bias
Biased sample
In statistics, sampling bias is when a sample is collected in such a way that some members of the intended population are less likely to be included than others. It results in a biased sample, a non-random sample of a population in which all individuals, or instances, were not equally likely to...
.
- A study published in the September 1996 Journal of Urology concluded that average erect length was 12.9 cm (5.08 in) (measured by staff). The purpose of the study was to “provide guidelines of penile length and circumference to assist in counseling patients considering penile augmentation.” Erection was pharmacologically induced in 80 physically normal American men (varying ethnicity, average age 54). It was concluded: “Neither patient age nor size of the flaccid penis accurately predicted erectile length.”
- A study published in the December 2000 International Journal of Impotence Research found that average erect penis length in 50 Jewish Caucasian males was 13.6 cm (5.35 in) (measured by staff). Quote: "The aim of this prospective study was to identify clinical and engineering parameters of the flaccid penis for prediction of penile size during erection." Erection was pharmacologically induced in 50 Jewish Caucasian patients who had been evaluated for erectile dysfunctionErectile dysfunctionErectile dysfunction is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance....
(average age 47±14y). Patients with penis abnormalities or whose ED could be attributed to more than one psychological origin were omitted from the study. - A study conducted by LifeStyles Condoms found an average of 14.9 cm (5.9 in) with a standard deviation of 2.1 cm (0.8 in) (measured by staff). The purpose of this study was to ensure properly sized condoms were available.
- A review published in the 2007 issue of BJU International showed the average erect penis length to be 14–16 cm (5.5–6.3 in) and girth to be 12–13 cm (4.7–5.1 in). The paper compared results of twelve studies conducted on different populations in several countries.
- An Italian study of about 3,300 men concluded that stretched length was measured on average to about 5 inches (13 cm). In addition, a correlation between weight and height and penis length was also found. However this was done only on 500 men and has very little correlation value.
Erect circumference
- The Cancún LifeStyle study, in which the circumference of the shaft was measured at three points (base, mid-shaft, and just below the head) and then averaged, found an average of 12.63 cm (4.972 inches) with a standard deviation of 1.3 cm (0.5 in).
Similar results exist regarding studies of the circumference
Circumference
The circumference is the distance around a closed curve. Circumference is a special perimeter.-Circumference of a circle:The circumference of a circle is the length around it....
of the adult fully erect
Erection
Penile erection is a physiological phenomenon where the penis becomes enlarged and firm. Penile erection is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal...
penis, with the measurement taken mid-shaft. As with length, studies that relied on self-measurement consistently reported a significantly higher average than those with staff measuring.
Flaccid length
One study found the mean flaccid penis length to be 3.5 inches (8.9 cm) (measured by staff). A review of several studies found average flaccid length to be 9–10 cm. Length of the flaccid penis does not necessarily correspond to length of the erect penis; some smaller flaccid penises grow much longer, while some larger flaccid penises grow comparatively less.The penis and scrotum can contract involuntarily in reaction to cold temperatures or nervousness, referred to by the slang term "shrinkage", due to action by the cremaster muscle
Cremaster muscle
-Contraction:Its function is to raise and lower the testes in order to regulate the temperature of the testes and promote spermatogenesis. Contraction may also occur during arousal which can prevent injury to the testicles during sex....
. The same phenomenon affects cyclist and exercise bike users, with prolonged pressure on the perineum from the saddle
Bicycle saddle
A bicycle saddle, often called a seat, is one of three contact points on an upright bicycle, the others being the pedals and the handlebars.The bicycle saddle has been known as such since the bicycle evolved from the draisine, a forerunner of the bicycle...
, and the straining of the exercise causing the penis and scrotum to contract involuntarily. An incorrect saddle may ultimately cause erectile dysfunction
Erectile dysfunction
Erectile dysfunction is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance....
(see crotch pressure for more information).
Flaccid penis length is a poor estimate of erect length; a better estimate is stretched length, that is 12–13 cm, as shown in review by Wylie and Erdley.
Micropenis
An adult penis with an erect length of less than 7 cm or just over 2 inches but otherwise formed normally is referred to in a medical context as having the micropenisMicropenis
Micropenis is an unusually small penis. A common criterion is a dorsal erect penile length of at least 2.5 standard deviations smaller than the mean human penis size. The condition is usually recognized shortly after birth...
condition. The condition affects 0.6% of men. Some of the identifiable causes are deficiency of pituitary growth hormone
Growth hormone deficiency
Growth hormone deficiency is a medical condition in which the body does not produce enough growth hormone . Growth hormone, also called somatotropin, is a polypeptide hormone which stimulates growth and cell reproduction...
and/or gonadotropin
Gonadotropin
Gonadotropins are protein hormones secreted by gonadotrope cells of the pituitary gland of vertebrates. This is a family of proteins, which include the mammalian hormones follitropin , lutropin , placental chorionic gonadotropins hCG and eCG and chorionic gonadotropin , as well as at least two...
s, mild degrees of androgen insensitivity
Androgen insensitivity syndrome
Androgen insensitivity syndrome is a condition that results in the partial or complete inability of the cell to respond to androgens. The unresponsiveness of the cell to the presence of androgenic hormones can impair or prevent the masculinization of male genitalia in the developing fetus, as...
, a variety of genetic syndromes, and variations in certain Homeobox
Homeobox
A homeobox is a DNA sequence found within genes that are involved in the regulation of patterns of anatomical development in animals, fungi and plants.- Discovery :...
genes. Some types of micropenis can be addressed with growth hormone or testosterone
Testosterone
Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...
treatment in early childhood. Operations are also available to increase penis size in cases of micropenis in adults.
Environmental influence on penis size
It has been suggested that differences in penis size between individuals are caused not only by geneticsGenetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
, but also by environmental factors such as culture
Culture
Culture is a term that has many different inter-related meanings. For example, in 1952, Alfred Kroeber and Clyde Kluckhohn compiled a list of 164 definitions of "culture" in Culture: A Critical Review of Concepts and Definitions...
, diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
, chemical/pollution exposure, etc. Endocrine disruptor
Endocrine disruptor
Endocrine disruptors are chemicals that interfere with endocrine in animals, including humans. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders...
resulting from chemical exposure has been linked to genital deformation in both sexes (among many other problems). Chemicals from both synthetic (e.g. pesticides, anti-bacterial Triclosan
Triclosan
Triclosan is an antibacterial and antifungal agent. It is a polychloro phenoxy phenol. Despite being used in many consumer products, beyond its use in toothpaste to prevent gingivitis, there is no evidence according to the American Food and Drug Administration that triclosan provides an extra...
, plasticizers for plastics, etc...) and natural (e.g. chemicals found in tea tree oil and lavender oil) sources have been linked to various degrees of endocrine disruption. Both PCBs
Polychlorinated biphenyl
Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...
and the plasticizer DEHP
Bis(2-ethylhexyl) phthalate
Bisphthalate, commonly abbreviated DEHP, is an organic compound with the formula C6H42. It is sometimes called dioctyl phthalate and abbreviated DOP. It is the most important "phthalate," being the diester of phthalic acid and the branched-chain 2-ethylhexanol. This colourless viscous liquid is...
have been associated with smaller penis size. DEHP metabolites measured from the blood of pregnant women have been significantly associated with the decreased penis width, shorter anogenital distance
Anogenital distance
Anogenital distance is the distance from the anus to the genitalia, the base of the penis or vagina. It is considered medically significant for a number of reasons, in both humans and animals. It is regulated by dihydrotestosterone, which can be disrupted by phthalates common in plastics...
, and the incomplete descent of testicle
Testicle
The testicle is the male gonad in animals. Like the ovaries to which they are homologous, testes are components of both the reproductive system and the endocrine system...
s of their newborn sons, replicating effects identified in animals. Approximately 25% of US women have phthalate levels similar to those in the study. A 2007 study by University of Ankara, Faculty of Medicine has found that penile size may decrease as a result of some hormonal therapy
Hormonal therapy (oncology)
Hormonal therapy is one of the major modalities of medical treatment for cancer, others being cytotoxic chemotherapy and targeted therapy . It involves the manipulation of the endocrine system through exogenous administration of specific hormones, particularly steroid hormones, or drugs which...
combined with external beam radiation therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
. In addition, some estrogen based fertility drugs like diethylstilbestrol
Diethylstilbestrol
Diethylstilbestrol is a synthetic nonsteroidal estrogen that was first synthesized in 1938. Human exposure to DES occurred through diverse sources, such as dietary ingestion from supplemented cattle feed and medical treatment for certain conditions, including breast and prostate cancers...
(DES) have been linked to genital abnormalities and/or a smaller than normal penis (microphallus).
Historical perceptions
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
an uncircumcised and small penis was culturally seen as desirable in a man, whereas a bigger or circumcised penis was viewed as comical or grotesque, usually being found on "fertility gods, half-animal critters such as satyr
Satyr
In Greek mythology, satyrs are a troop of male companions of Pan and Dionysus — "satyresses" were a late invention of poets — that roamed the woods and mountains. In myths they are often associated with pipe-playing....
s, ugly old men, and barbarians."
CBC
CBC Radio
CBC Radio generally refers to the English-language radio operations of the Canadian Broadcasting Corporation. The CBC operates a number of radio networks serving different audiences and programming niches, all of which are outlined below.-English:CBC Radio operates three English language...
radio has suggested, based on several sources, that ancient Romans
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
had a viewpoint contrary to that of the Greeks. This was also the case in medieval Arabic literature
Arabic literature
Arabic literature is the writing produced, both prose and poetry, by writers in the Arabic language. The Arabic word used for literature is adab which is derived from a meaning of etiquette, and implies politeness, culture and enrichment....
, where a longer penis was preferred, as described in an Arabian Nights tale called "Ali with the Large Member". As a witty satire
Satire
Satire is primarily a literary genre or form, although in practice it can also be found in the graphic and performing arts. In satire, vices, follies, abuses, and shortcomings are held up to ridicule, ideally with the intent of shaming individuals, and society itself, into improvement...
of this fantasy, the 9th century Afro-Arab
Afro-Arab
Afro-Arab refers to people of mixed Black African and genealogical Arab ancestral heritage and/or linguistically and culturally Arabized Black Africans...
author Al-Jahiz
Al-Jahiz
Al-Jāḥiẓ was an Arabic prose writer and author of works of literature, Mu'tazili theology, and politico-religious polemics.In biology, Al-Jahiz introduced the concept of food chains and also proposed a scheme of animal evolution that entailed...
wrote: "If the length of the penis were a sign of honor, then the mule
Mule
A mule is the offspring of a male donkey and a female horse. Horses and donkeys are different species, with different numbers of chromosomes. Of the two F1 hybrids between these two species, a mule is easier to obtain than a hinny...
would belong to the (honorable tribe of) Quraysh".
Penis size is also alluded to in the Bible
Bible
The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...
:
“In the same way, I became disgusted with Oholibah and rejected her, just as I had rejected her sister, because she flaunted herself before them and gave herself to satisfy their lusts.19 Yet she turned to even greater prostitution, remembering her youth when she was a prostitute in Egypt.20 She lusted after lovers with genitals as large as a donkey’s and emissions like those of a horse. Ezekiel 23:18–20, New Living TranslationNew Living TranslationThe New Living Translation is a translation of the Bible into modern English. Originally starting out as an effort to revise The Living Bible, the project evolved into a new English translation from Hebrew and Greek texts...
Male self-perception
Males may quite easily underestimate the size of their own penis relative to that of others, because of the foreshortening obtained from looking down, or because of the accumulation of fat at the base of the penis. A survey by sexologists showed that many men who believed that their penis was of inadequate size had average-sized penises. Another study found sex education of standard penile measurements to be helpful and relieving for patients concerned about small penis size, most of whom had incorrect beliefs of what is considered medically normal. The perception of having a large penis is linked to higher self esteem.Among gay men
A study undertaken at Utrecht University found that the majority of homosexual men in the study regarded a large penis as ideal, and having one was linked to self esteem. One study analysing the self-reported KinseyKinsey Reports
The Kinsey Reports are two books on human sexual behavior, Sexual Behavior in the Human Male and Sexual Behavior in the Human Female , by Dr. Alfred Kinsey, Wardell Pomeroy and others and published by Saunders...
data set found that homosexual men had statistically larger penises than their heterosexual counterparts. One potential explanation given is a difference in the exposure to androgen hormones in the developing embryo. Evidence points towards men of both orientations being equally likely to exaggerate the size of their penises.
Anxiety about penis size
Widespread private concerns related to penis size have led to a number of folkloreFolklore
Folklore consists of legends, music, oral history, proverbs, jokes, popular beliefs, fairy tales and customs that are the traditions of a culture, subculture, or group. It is also the set of practices through which those expressive genres are shared. The study of folklore is sometimes called...
sayings and popular culture
Popular culture
Popular culture is the totality of ideas, perspectives, attitudes, memes, images and other phenomena that are deemed preferred per an informal consensus within the mainstream of a given culture, especially Western culture of the early to mid 20th century and the emerging global mainstream of the...
reflections related to penis size. Penis panic
Penis panic
Koro is a culture-specific syndrome from Southeast Asia in which the patient has an overpowering belief that his penis is shrinking and will shortly disappear. Also known as shrinking penis, the syndrome is listed in the Diagnostic and Statistical Manual of Mental Disorders...
is a form of mass hysteria involving the believed removal or shrinking of the penis, known as genital retraction syndrome
Genital retraction syndrome
Koro is a culture-specific syndrome from Southeast Asia in which the patient has an overpowering belief that his penis is shrinking and will shortly disappear. Also known as shrinking penis, the syndrome is listed in the Diagnostic and Statistical Manual of Mental Disorders...
. The penis can significantly shrink due to scar tissue formation from a condition called Peyronie's disease
Peyronie's disease
Peyronie's Disease Peyronie's Disease Peyronie's Disease (also known as "Induratio penis plastica", or more recently Chronic Inflammation of the Tunica Albuginea (CITA), is a connective tissue disorder involving the growth of fibrous plaques in the soft tissue of the penis affecting up to 10% of men...
which affects up to 10% of men. Products such as penis pumps, pills, and other dubious means of penis enlargement
Penis enlargement
Penis enlargement procedures are techniques alleged to make the human penis increase in girth, length, or hardness. Often, in the course of advertising fraudulent products, the distinction between temporary enlargement, i.e...
are some of the most marketed products in email spam. At present there is no consensus in the scientific community of any non-surgical technique that permanently increases either the thickness or length of the erect penis that already falls into the normal range (4.5" to 7").
Penis size and size of other body parts
There is evidence both for and against a link between penis size and the size of other body parts. One study found a weak correlation between the size of the stretched penis and foot size and height. Another investigation failed to find any evidence for a link between shoe size and stretched penis size.A potential explanation for a link is that the development of the penis in an embryo is controlled by some of the same Hox genes (in particular HOXA13
HOXA13
Homeobox protein Hox-A13 is a protein that in humans is encoded by the HOXA13 gene.- Function :In vertebrates, the genes encoding the class of transcription factors called homeobox genes are found in clusters named A, B, C, and D on four separate chromosomes. Expression of these proteins is...
and HOXD13
HOXD13
Homeobox protein Hox-D13 is a protein that in humans is encoded by the HOXD13 gene.This gene belongs to the homeobox family of genes. The homeobox genes encode a highly conserved family of transcription factors that play an important role in morphogenesis in all multicellular organisms...
) 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
Hand-Foot-Genital Syndrome
Hand-foot-genital syndrome is characterized by limb malformations and urogenital defects. Mild bilateral shortening of the thumbs and great toes, caused primarily by shortening of the distal phalanx and/or the first metacarpal or metatarsal, is the most common limb malformation and results in...
).
Studies of size preferences among sexual partners
A study published in BMC Women's Health surveyed women's preferences concerning penis size and concluded that width rather than length is a more important factor of sexual stimulation.Similar results were found in a cover story published in Psychology Today
Psychology Today
Psychology Today is a bi-monthly magazine published in the United States. It is a psychology-based magazine about relationships, health, and related topics written for a mass audience of non-psychologists. Psychology Today was founded in 1967 and features articles on such topics as love,...
, which surveyed 1,500 readers (about 2/3 women) about male body image. Many of the women were not particularly concerned with penis size and over 71% thought men overemphasized the importance of penis size and shape. Generally, the women polled cared more about width than men thought, and less about length. "...the number one reason women preferred a thicker penis was that it was more satisfying during intercourse."
Another study, conducted at Groningen University Hospital, asked 375 sexually active women (who had recently given birth) the importance of penis size and concluded: "Although clearly in the minority, a nevertheless considerable percentage of the women respondents attached substantial importance to the size of the male sexual organ".
The term size queen is slang for a person who prefers their sexual partner(s) to have a larger-than-average penis.
Comparison to other primates
When compared to other primatePrimate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s, including large primates such as the gorilla
Gorilla
Gorillas are the largest extant species of primates. They are ground-dwelling, predominantly herbivorous apes that inhabit the forests of central Africa. Gorillas are divided into two species and either four or five subspecies...
, the genitalia of male humans are large. The human penis is both longer and thicker than that of any other primate, both in absolute terms and in relative size to the rest of the body.
(see Implications of differences in penis length and morphology for hypothesized advantages involving group sex which may have led to the evolution of a larger penis size in humans, and factors which may account for differences in average penis size within the human species).
Penis size and condom use
One Australian study of 184 men looked at penis length and circumference in relationship to condom breakage or slippage. 3,658 condoms were used. The study found that condoms, when used correctly, had a breakage rate of 1.34% and, of slippage, 2.05%, with a total failure rate of 3.39%. Penis length did not influence slippage, but penis circumference and broken condoms were strongly correlated, with larger sizes increasing the rate of breakage.See also
- Penis envyPenis envyPenis envy in Freudian psychoanalysis refers to the theorized reaction of a girl during her psychosexual development to the realization that she does not have a penis....
- MicropenisMicropenisMicropenis is an unusually small penis. A common criterion is a dorsal erect penile length of at least 2.5 standard deviations smaller than the mean human penis size. The condition is usually recognized shortly after birth...
- PhalloplastyPhalloplastyPhalloplasty refers to the construction of a penis or, sometimes, artificial modification of the penis by surgery, often for cosmetic purposes. It is also occasionally used to refer to penis enlargement....
- Penis enlargementPenis enlargementPenis enlargement procedures are techniques alleged to make the human penis increase in girth, length, or hardness. Often, in the course of advertising fraudulent products, the distinction between temporary enlargement, i.e...
- Sexual selection in human evolutionSexual selection in human evolutionCharles Darwin described sexual selection as depending "on the advantage which certain individuals have over others of the same sex and species solely in respect of reproduction". In animals, he saw the competition for advantage as occurring between males - the most successful of which were chosen...
- The Third ChimpanzeeThe Third ChimpanzeeThe Third Chimpanzee: The Evolution and Future of the Human Animal is a wide-ranging book by Jared Diamond, professor of geography and physiology at the University of California, Los Angeles , which applies insights from biology, anthropology, and linguistics to questions such as why one species...
- Why is sex fun?