A very long penis can cause dispareunia, if the man doesnt understand how to use it carefully. 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 when used correctly, condoms had a breakage rate of 1.34% and a slippage rate of 2.05%, for a total failure rate of 3.39%. Penile dimensions did not influence slippage, although penis circumference and broken condoms were strongly correlated, with larger sizes increasing the rate of breakage. Biochemistry
Androgens like testosterone are responsible for penis enlargement and elongation during puberty. Penis size is positively correlated with increasing testosterone levels during puberty. But after puberty, administration of testosterone does not affect penis size, and androgen deficiency in adult men only results in a small decrease in size. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are also involved in penis size, with deficiency (such as that observed in growth hormone deficiency or Laron syndrome) at critical developmental stages having the potential to result in micropenis. Variance
Grower vs shower
A 2018 study differentiates two types of penises based on the change they experience from flaccid to erect. It distinguishes between growers and showers. Growers or penises of blood grow more than 4 cm with respect to their flaccid state, and showers or penises of meat grow less of 4 cm. Genetics
There are certain genes, like homeobox (Hox a and d) genes, which may have a role in regulating penis size.
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. See also
Digit ratio
Human vaginal size
Jonah Falcon
Penis enlargement
Penis envy
Phalloplasty
Sexual selection in humans
The Third Chimpanzee
Why Is Sex Fun? References
Citations
General and cited sources
"Men worry more about penile size than women, says 60-year-old research review" (Press release). Blackwell. 31 May 2007. Retrieved 11 August 2018. Lee, P. A; Mazur, T; Danish, R; Amrhein, J; Blizzard, R. M; Money, J; Migeon, C. J (1980). "Micropenis. I. Criteria, etiologies and classification". The Johns Hopkins Medical Journal. 146 (4): 156–63. PMID 7366061. NAID 10010056499. Lauersen, Niels; Whitney, Steven (1983). Its Your Body: A Womans Guide to Gynecology (3rd ed.). New York: Berkley Publishing. p. 480. ISBN 978-0-425-09917-9. Rushton, J.Philippe; Bogaert, Anthony F (1987). "Race differences in sexual behavior: Testing an evolutionary hypothesis". Journal of Research in Personality. 21 (4): 529–51. doi:10.1016/0092-6566(87)90038-9. Sutherland, Ronald S; Kogan, Barry A; Baskin, Laurence S; Mevorach, Robert A; Conte, Felix; Kaplan, Selna L; Grumbach, Melvin M (1996). "The Effect of Prepubertal Androgen Exposure on Adult Penile Length". The Journal of Urology. 156 (2): 783–7, discussion 787. doi:10.1016/S0022-5347(01)65814-2. PMID 8683783. == External links ==