The Science of Penis Size: The Truth About Race, Evolution and Genetics
This article explores the scientific reality behind penis size stereotypes. By analysing clinician-measured data from global studies, we debunk the myth that race is the primary factor in size.
Instead, we turn to evolutionary biology to explain why human males—regardless of race—possess larger genitalia than other primates. Featuring insights from anthropologists and biologists, we discuss how bipedalism (walking upright) and millions of years of female selection shaped the modern male anatomy.
Introduction:
For decades, the topic of penis size has been surrounded by myths, stereotypes, and curiosity. One of the most pervasive beliefs is that Black men possess significantly larger penises than men of other races.
While pop culture often treats this as a given, scientific data paints a more nuanced picture. Below, we explore what the actual numbers say and examine the fascinating evolutionary theories explaining why human men—of all races—developed larger members than our primate cousins.
What the Data Says: The Numbers
When discussing penis size, it is critical to distinguish between self-reported data (which is often exaggerated) and clinician-measured data (which is scientifically accurate).
A landmark systematic review published in the BJU International (British Journal of Urology) analysed data from over 15,500 men worldwide. The study, led by Dr David Veale, aimed to create a standard “nomogram” for penis size.
The study found the following global averages for men across all groups:
- Average Flaccid Length: 9.16 cm (3.61 inches)
- Average Erect Length: 13.12 cm (5.16 inches)
- Average Erect Girth: 11.66 cm (4.59 inches)
Do Black men rank higher in penis size?
Contrary to the common stereotype, the most rigorous scientific studies show that the link between race and penis size is weak or non-existent.
- The BJU International study found no strong evidence of penile size differences linked to race.
- A separate study published in the Tropical Journal of Medical Research, which specifically measured 115 Nigerian men, found an average stretched length of 13.37 cm (5.26 inches). This is statistically very similar to the global average of 13.24 cm (5.21 inches) found in Veale’s international dataset.
While some datasets suggest minor regional variations, the scientific consensus is that individual genetics plays a much larger role than race.
The Evolutionary Perspective: Why Size Matters
If racial differences are minimal, why do humans generally have large penises compared to other primates? For context, a 400lb male gorilla has an erect penis of only about 1.25 inches.
Experts attribute the size of the human penis to millions of years of evolutionary pressure that began with our ancestors in Africa.
1. The Theory of Female Choice
Loretta A. Cormier, a Professor of Anthropology at the University of Alabama, argues that the evolution of the human penis was largely driven by female selection. In her work, she suggests that ancient women were the directors of this evolution.
Unlike other primates, early human females may have selected mates based on physical traits that signalled health or genetic fitness. Over roughly 6 million years of evolution, women’s preference for certain traits resulted in the male anatomy we see today. Simply put, female social and sexual choices had serious evolutionary consequences for the male body (Cormier & Jones, 2015).
2. Upright Posture and “Advertising”
Dr Darren Curnoe, an evolutionary biologist, offers a complementary theory involving our transition to bipedalism (walking on two legs).
According to Curnoe, the size of a primate’s genitalia is usually determined by the level of competition for females. Chimpanzees, for example, have large testicles but medium penises because they engage in “sperm competition”—where multiple males mate with one female. Humans, however, evolved differently.
Curnoe suggests that when early humans stood upright, the penis became more visible. Because human females do not have a distinct “estrus” phase (heat) like chimpanzees, males had to find other ways to attract mates.
- The “Signalling” Effect: Walking on two feet left the penis out in the open. A larger, more visible penis served as an anatomical “advertisement” to potential mates.
- Thermoregulation: Curnoe also theorises that a longer penis may have helped release body heat—an essential adaptation for early humans living in the hot climates of ancient Africa.
Conclusion
While the stereotype that Black men are significantly larger than other races is not strongly supported by clinician-measured data, the history of the human penis is undeniably rooted in Africa.
It was there, millions of years ago, that the pressures of upright walking and female selection shaped the human male anatomy. The “endowment” of modern men is likely a result of these ancient evolutionary successes, shared by the species as a whole.
References
- Cormier, L. A. (2016). The Domesticated Penis: How Womanhood Has Shaped Manhood. University of Alabama Press. https://www.uapress.ua.edu/9780817358914/the-domesticated-penis/
- Orakwe, J., & Ebuh, G. (2009). “Oversized” Penile Length In The Black People: Myth Or Reality. Tropical Journal of Medical Research, 11(1). https://doi.org/10.4314/tjmr.v11i1.30465
- UNSW. (2025). Size does matter, and so does researching why. UNSW Sites. https://www.unsw.edu.au/newsroom/news/2013/04/size-does-matter-and-so-does-researching-why
- Veale, D., Miles, S., Bramley, S., Muir, G., & Hodsoll, J. (2015). Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15 521 men. BJU International, 115(6), 978–986. https://doi.org/10.1111/bju.13010
Frequently Asked Questions
What is the average penis size globally?
According to a systematic review published in the BJU International, which analysed data from over 15,000 men, the average flaccid length is 9.16 cm (3.61 inches), and the average erect length is 13.12 cm (5.16 inches).
Is the myth about Black men having larger penises true?
Scientific data does not support the stereotype that Black men are significantly larger than men of other races. Clinical studies, including data from Nigerian men, show averages that are statistically very similar to the global average. Most variations in size are due to individual genetics, not race.
Why do humans have larger penises than other primates?
Evolutionary biologists like Dr Darren Curnoe suggest that human bipedalism (walking upright) played a major role. Unlike chimpanzees, whose genitalia are hidden, the human penis is visible. Over millions of years, a larger size may have evolved to “advertise” potential mates or to help regulate body heat in hot climates.
How did female choice shape male anatomy?
Anthropologist Loretta A. Cormier theorises that ancient women directed the evolution of the penis through sexual selection. Early human females likely preferred mates with specific physical traits, and over generations, these choices influenced the size and shape of the modern male penis.
The only 2 Scientific studies that have been conducted (Dr Masters and by Dr Kinsey) on penis size showed when the two studies are averaged together that there was no racial difference between Blacks and Whites. Most African studies have been "self measured" studies which is why those countries have an "enhanced" size compared to African Americans. Blacks do not have bigger penises than other races as proved in America, the African "studies" are not properly measured hence the rise in average length for blacks.
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I’m a white male South African and I can say black males do not have bigger penis’ in actual fact the Afrikaans white male had the biggest penis in the gym of Virgin Active gyms I saw all the members and African men are in average smaller than the white Afrikaans man
Know you doing racist things by saying white men have large penises Any individual penis size can’t determine by Race
this stereotypes also spread be black people too
I’m a 35 year old divorced white lady, and since I started dating again, I’ve had sexual relations with 12 different men, and I’ve noticed that the African American men that I’ve dated have larger penises than men of other races. Penis size matters somewhat to me, because I have more intense orgasms during intercourse with men who have larger penises.
Who said anything about only blacks and whites? There are more races shown on the graph then just blacks and whites, stop being insecure.
Thank you for that. I’m white German and over my youth my penis has shrunk depending on my diet, exercise and medications from 9″ to 5″. Only recently (now 41 and after 10 years) has it begun to grow again with me finding new ways to get aroused. Now back to 7.5″ and I’m happy with that.
I’ve seen plenty of Asian (Indian, Japanese etc) dicks that are super thick and long. Unless your gonna search all men in the world u will never know. Still want some chocolate cream pie tho………..
I’m South African so I know the black male is not bigger as in gym we all get naked and it’s actually in fact the Afrikaans white male that has the big penis so myth totally busted
Your clearly self conscious because there’s more black men then just in African black males. There are black men in the USA as well as the uk, Jamaica, Columbia as well as other countries France etc. Regardless of where you are clearly African white males are the same mindset as white men of the USA, anytime there is a study showing that they don’t beat everyone else they have to explain why they’re right and studies are wrong. Who cares about penis size everyone has one.
Great Article And from personal experience I would have to say chocolate is much more bigger the rest also.
Im a gay dude, kind of a penis expert. Id say asian dudes tend to be smaller, white guys are kinda average, and most of the black dudes ive been with have been larger, have more stamina and can put in the work. Just my experience.
I’m a gay dude as well. My opiniom and experience is different. The biggest penis I Have seen was black, but two smallet ones were black too… All the others were average, Just like white. Not small, but not big, about 6 to 7 inches. Not much experience with other races to form an oponion.
Hi Watsup am gay too
Gay Male and Athlete, I dated and seen many types and races of men with all types of penis length. Black men clearly have larger in both length and width in the penis department…one thing though they tend to not get as hard as the average White of Asian penis in my humble experience…as noted above they also excell in the stamina department.
Averages are averages. However the largest, thickest and longest I’ve ever saw where all black. That’s what Magnums are for.
When I was in the military back in the 70’s I saw a lot of naked black and white men. In the flaccid state I saw no real difference. However, there was always one or two white and black guys with obviously big dicks. At least when they were flaccid. I actually saw more big dick white guys than black. One last thing, these well endowed guys were all in the average height range of 5’8″ to 5’10”. I didn’t see any tall guys with the big packages.
African-American gay black men who are
gay truck drivers between 21 – 35 years old
were able to experience sexual gratification
from a glory hole inside the men’s rest room
at a gay bar in Flint Michigan from
physically disabled gay white men between
21 – 35 years old who are size queens
before the black Friday sales
in Flint Michigan
Not feeling it.
i definitely can say my black fuck buddy who just happens to be a sub for some reason has a huge dick but and im white so i find it really whack that i have just about as much dick size and i actually have a shitload more stamina(talkin like 4.5 hours ifucked this guy’s brains out)
It’s just a stereotype that porn made to be bigger (no pun intended) than the reality of it. I’ve even seen an interview with a black pornstar saying a german pornstar who was white had a bigger piece than he even had. It’s just what sells due to it being art in a sense. Black man. White woman.
Honestly, I’d like to see more black women with white men. You want to talk about a real racist injustice. They don’t nearly get enough screen time.
I call BS on the evolutionary explanation in this article. In primates it’s all about dominance and in a natural group setting the big piece males are on average always larger and more dominant. Not because of the big piece. The big piece is simply, on average, attached to the bigger males and bigger males are on average more dominant, which means they mate with more females. That’s the evolutionary drive for bigger penises in primitive primate-like cultures that existed much longer (and continue to exist) in the so called third world areas. It has nothing to do withe “advertising”. The “normal” sizes are therefore more prevalent in more advanced societies where dominance or aggression don’t play such an important role in mating success. In other words, you’ll find, on average, a larger number of big penises amongst dominant males in any ethnic group. Visual attraction to bigger pieces, bigger breasts, bigger butts etc is modern man’s cultural nonsense. An average 15 cm sized penis is in no way deficient compared to a 25 cm penis. It can be actually the other way around, because the average vagina depth is around 14 cm, so mating with a 25+ cm piece male is uncomfortable or even painful to most females. It is not uncommon that a big piece males have trouble having sex because a large penis is also on average thicker and makes penetration more difficult, sometimes even impossible and won’t fit fully inside the vagina, which lowers the male’s “pleasure index”. So to sum it up, the obsession with large penises is a modern cultural perversion and most “good girls” will prefer an average sized piece to a macho trunk. That is why the porn industry prefers big pieces. Both the porn industry’s men and women are the carriers of cultural perversion and have, on average, bigger penises and vaginas, which do not represent the global average males and females. They actually represent the primate-like primitive social portion of population in advanced society. Not primitive intellectually, but behaviourally. Let me make it clear that people come in different shapes and sizes, so variation in behaviour is neither unexpected nor bad. It is simply a fact of life and a part of being a higher primate, and in a modern law governing society the porn industry and its related social groups are the healthy arena for this evolutionary heritage.
It seems that I have read a story before where females have different sized vagina’s and they even had them broken down by the category of size. That being said, a woman with a shallower vagina will need a smaller sized penis for compatibility. You can’t expect a 9 inch penis to penetrate a shallow vagina and it be mutually pleasurable for both parties. I am not overly well versed on gay men, but I do know that the anus and rectum have size variations according to depth. I would imagine a lot of gay men will accommodate larger penis size. I know I have heard some Down Low men explain that they rather have sex with a gay man as he has more depth and they are more likely to get it all in. In short, there really is someone for everyone and you can attempt to “display” your penis if you like, but we all wear clothes and being covered up don’t give a real glimpse of what anyone is packing. I know a friend that wears briefs, gym short and regular jeans and he says it is to flatten out any bulges. I have seen some guys wear loose fitting pajama bottom type pants and loose fitting sweats, but they will show everything if they are not careful with how they move. I don’t see it often, but there has been a time or two that the dick print was visible and I quickly looked away as I didn’t want to calculate size in my mind. I put it this way, it probably rank on some of the longest flaccid like 7 inches or so and I am sure that is more than the average man has fully erect. Both times, the long flaccid one was on a black man.
It most certainly is a myth but if your self-esteem needs to believe it, hey man. More power to you. I happen to be a Ghanaian with excellent self-esteem. I don’t need to believe lies to feel good about being black.
I probably think this website wants to spread stereotypes too even if we see those data the difference is just minimal
I’m an 18 year old college student, and I first became sexually active when I was a junior in high school. I was 16 the first time I had intercourse, and since then I’ve had probably 7 sexual partners. I was in a relationship with two black men and I noticed that their penises were a lot larger than most of my other boyfriends penises. I think an average sized penis feels more comfortable in my vagina, and it’s easier for me to perform fellatio on a man with an average sized penis.
64% of very tall able bodied gay black men
with very long, and very thick, and
very large black penises that are
gay truck drivers between 35- 49 years old
were able to experience anonymous
sexual gratification from physically disabled
gay white men between 35 – 49 years old
under the handicapped stall inside both of the
men’s restrooms at the
M – 33 rest area in West Branch, MI.
before the “Black Friday Sales
in West Branch, MI.
I am a able bodied heteroflexible white male
who was born in the city of Flint, Michigan
on August 13, 2004 and I have been a
sex worker since I was 18 years old
and I charged $ 175.00 to able-bodied
African-American gay men for fellatio
if they want me to perform fellatio on them
if able bodied African-American gay men
or African-American physically disabled
gay men between 18 – 39 years old
are not well endowed and I will do anything
that it takes to pay my bills and put
food on my table and have a roof under
my head and if you think that I am a racist
you are dealing with the wrong person
sorry for your luck, it sucks to be you
you fuckin black cock sucking
black coons mother fuckers!!
Now does it cycle!! 🚲