Why Do Men Have Nipples?

By: Cristen Conger  | 

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Author's Note: Why Do Men Have Nipples

It's well established that Barbie isn't exactly designed according to naturally occurring female measurements. Her chiseled boyfriend Ken isn't a perfect chip off the ol' human male block, either. Sure, his abs of steel (or plastic, rather) are achievable via Malibu-caliber diets and exercise, but no gym rat will ever be able to sculpt pectorals quite that smooth since Ken -- and Barbie, too, for that matter -- has no nipples. But that doesn't imply that Ken is somehow less of a (fake) man for not having them. Evolutionary biologists have long puzzled over why male nipples have hung around the male chest for so long considering the minimal purpose they serve, aside from offering another enticing spot for a body piercing. Some consider them useless enough to qualify as vestigial anatomy. And in that light, when you think about it, nipple-less, wisdom-teeth-free and appendix-absent Ken could be the model of a future, more highly evolved man. That said, he would also be a man unable to reproduce and pass along that hunky musculature, Ken's ultimate Achilles heel.

Related Articles

  • Adams, Cecil. "Why do men have nipples?" Straight Dope. May 18, 1979. (Sept. 26, 2012)
  • Diamond, Jared. "Father's Milk." Discover. February 1995. (Sept. 26, 2012)
  • Kaneshiro, Neil K. "Hormonal effects in newborns." MedlinePlus. (Sept. 26, 2012)
  • Lawrence, Eleanor. "Why do men have nipples?" Nature. Aug. 05, 1999. (Sept. 26, 2012)
  • Mayo Clinic. "Galactorrhea." June 22, 2010. (Sept. 26, 2012)
  • McCarthy, Susan. "Why do men have nipples?" Salon. June 08, 1999. (Sept. 26, 2012)
  • Miller, Brandon. "Top 10 Useless Limbs (and Other Vestigial Organs)." LiveScience. Feb. 09, 2005. (Sept. 26, 2012)
  • Mimouni F.; Merlob, P.; and Reisner, SH. "Occurrence of supernumerary nipples in newborns." American Journal of Disabilities in Children. Vol. 137. No. 10. October 1983. (Sept. 26, 2012)
  • Moorehead, Joanna. "Are the men in the African Aka tribe the best fathers in the world?" The Guardian. June 14, 2005. (Sept. 26, 2012)
  • National Cancer Institute. "Breast Cancer." National Institutes of Health. (Sept. 26, 2012)
  • Schmidt, H. "Supernumerary nipples: prevalence, size, sex and side predilection – a prospective clinical study." European Journal of Pediatrics. Vol. 157. No. 10. October. 2010. (Sept. 26, 2012)
  • Serrano, Shea. "Can Men Breastfeed?" Mental Floss. Nov. 13, 2008. (Sept. 26, 2012)
  • Simons, Andrew M. "Why do men have nipples?" Scientific American. Sept. 17, 2003. (Sept. 26, 2012)
  • Swaminathan, Nikhil. "Strange but True: Males Can Lactate." Scientific American. Sept. 06, 2007. (Sept. 26, 2012)
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Male Nipple FAQ

Is the male nipple sensitive?
The sensitivity of a person's nipples varies, regardless of a person's sex. Some men have very sensitive nipples while others do not.
Why do men have nipples?
The simplest explanation is that all human embryos start out with nipples and evolution didn't get around to selecting against their existence on the male chest.
What is the function of the male nipple?
Inappropriate lactation, also known as galactorrhea, can affect men, but it’s incredibly rare. Otherwise, men's nipples don't really have a function.
Why do men's nipples sometimes get bigger?
Puffy nipples in men are fairly common, resulting from enlarged breast glands. This can be due to low testosterone levels, steroid use, or excess fat.
Why do men's nipples harden?
Just like females, males have areolas (the colored area surrounding the nipples). These smooth muscle cells contract when stimulated (including getting cold!), increasing blood flow to the nipple and causing it to harden. In many cases, this also increases the sensitivity of the nipple, regardless of the person's sex.