When it comes to women, it makes sense why they have nipples – evolution has placed the job of lactating infants to them; but, what about men? Why do they have nipples?
Science tells us it is because everyone’s body is first developed as a female in the womb.
In the first few weeks, the embryo develops in the caricature of the female. In fact, it takes the mother’s genes and develops some characteristics of the mother. At this stage, the reproductive organs, nipples and everything start developing in the embryo. To this point, gender doesn’t play a role. The organs develop indifferent to the gender.
It is only after 8 prolonged weeks, when the Y chromosome kicks in and the feminine genes stop developing in the body. If this Y chromosome is not present, then obviously the child is female and she will grow and develop all organs as the female does.
But if the Y chromosome is present, the clitoris will transform into a fully grown scrotum and penis, and then the female grown labia will fuse.
So the fact is that primarily everyone in the womb is first a female. 8 weeks is a long time; and to develop the traits of the X chromosome up to that point means they are developing initially with the X chromosome. Later on, they develop with the traits of the Y chromosome, that is to say, if the Y chromosome is present in the offspring.
This is why when the Y chromosomes kick in, the male nipples stop developing lactating qualities or post birth breast developmental qualities.
So in a way, we can actually say that men not only have nipples, but actually those are underdeveloped breasts.
Hence, it might be a common misconception that breast cancer occurs only in women, as it can happen in men as well. However, the incident of breast cancer in men is very less, as a mere 1% of the males may actually develop breasts when afflicted with breast cancer.