I mean, think about it. From an evolutionary standpoint, with reproduction being the ultimate goal of a species, it makes no sense. Women can only have a kid every nine to ten months, but men could go a couple of times a day. Yet with humans, along with almost every other vertebrate, men and women are born in equal numbers. (Yes, I know it's more like 51% to 49%, asshole. You know who you are.) Why didn't we evolve to give birth to tons of females and just a few males? It would have led to much faster population growth. Now, I know there are going to be people who say I don't understand reproduction, or I don't understand evolution. So here's a quick summary of how I imagine that this increased likeliness for females would developed: Sex is determined by whether a person has two XX chromosome, making them female, or one X and one Y chromosome, making them male. The female eggs all have one X chromosome, because the female has only X chromosomes. The male sperm also has one chromosome, either an X or a Y, because males have both X and Y chromosomes. When the sperm and egg meet, the chromosome possessed by the sperm determined the sex of the child to be. Now, suppose that a person has a mutation. Maybe it's something that makes X sperm swim faster. Maybe it's something that makes the Y sperm swim slower. Over the eons, it's very likely that a mutation would have occurred at some point to make a person's odds of having a daughter better than their odds of having a son. In a world where people had dozens of children, and where sex was literally an organisms only reason for existence, this mutation should have spread like wildfire. Think about it: Say an ancient couple has 5 sons and 5 daughters. They all grow up and pair off with some other people in monogamous relationships. The original couple can now get no more than ten grandchildren every nine months. Now say that couple instead has only one son and nine daughters. Each of the daughters can have one grandchild every nine months or so. However, the one son can go off and impregnate several other women, thus giving the original couple more grandchildren than if they had an even number of sons and daughters. Thus, the 90/10 gene would spread faster than the 50/50 gene. So why are we today 50/50(or 51/49, whatever) instead of 90/10, or even 99/1? Why do we have even numbers an monogamy when uneven numbers an polygamy would lead to increased population growth? ... I'm probably going to get called out for being sexist or something. So I'm just going to state a few more things. I think I'll put them in bold, too, with some underlines. Just so people won't miss them. [b][u]I am not saying that a woman's sole purpose is to bear children. I'm saying that reproduction is the primary goal of every organism, or at least it was until sentience came along. This post is not me wanting to there to be more women for the sake of having less competition or anything like that. I'm voicing legitimate scientific curiosity. [/u][/b] TL;DR: Women should logically outnumber men because it would be beneficial from an evolutionary standpoint.