Why Do Men Have Nipples?

“Why do men have nipples?” is not one that can be readily answered by scientists, but it is, nonetheless fascinating. Perhaps a better question than “Why do men have nipples?” is “Why can’t men nurse babies?” since they do, in fact, have nipples and even milk ducts. If a man were given a certain dosage of estrogen, a female hormone, he would be able to lactate like any woman. Such capability would give new meaning to the title of “Mr. Mom”, and we might see even the most macho CEO take breaks to pump a little milk at the office. One may wonder why do men have nipples and milk ducts when the capacity for milk production is not given naturally? For this, scientists have only a partial explanation.

As most people know, we are each given 23 pairs of chromosomes which determine all of our natural traits. Some traits are sex-determined and some are not. For instance, we are all given the natural ability to grow hair. But the ability to grow a mass of hair on our chins in the form of a beard is a sex-determined trait and is usually given only to men (notwithstanding the occasional bearded lady you might see at the circus or the popularity of waxing among beauticians). It is possible that nipples and milk ducts, what we would ordinarily would think of as sex-determined traits are actually general traits, and that the actual lactation is sex-determined. However, this doesn’t completely answer the question “Why do men have nipples” in the first place.

Another partial explanation that all fetuses are asexual and begin to develop characteristics of males and females later on in the gestation period. Nipples are developed before males are distinguished from females. But this leads to a further question; if male nipples are meant to stop developing after the fetus shows other signs of being male, then why aren’t men born with fetus-sized nipples? The question “Why do men have nipples?” is an interesting one and leads to a fascinating discussion of the natural parenting roles of men and women.