Why are there so less female chess-players?

Not sure, I do know that my dad taught me chess and my mom doesn't know how to play.  Could be due to lack of interest.  After all, it's a dumb game where you have to think and can't even dress up the pieces...

We have got lizardbrains! Deep inside under the neocortex which does the more advanced stuff like reasoning, is the reptillianbrain where our deepest and oldest habits are 'seated', like fear. Not sure if it has alot to do with partnerselection, but there is no need for too. Also the whole evolutionary thing isn't that mumbo jumboish! 

I admit straight away that social construct also has to do alot with it. Therefore more men play, and more men = bigger chance of champions being men.

But think of this example:
60 cave(wo)men: 30 male + 30 female

10 males are strong and fit 
10 males are not so strong, but they are very kind
10 males are weak
15 beautiful women 
15 not so good looking women

Natural selection: (for the example only males will get selected)

Flu strikes when these men are kids: 
4 strong get infected, 2 die
5 not so strong get infected, 3 die
6 weak get infected, 4 die
 

When they are middle aged they have fights to establish their position in the group:
2 strong guys die
3 not so strong kind guys die, they are friendly and dont get fighted that much
4 weak guy dies

And not to forget the factor (bad) luck:
1 strong man is struck by lightning and dies.

So by the time they are ready to mate we are left with:

5 strong guys
4 nice guys
2 weak guys

Sexual selection

30 women can now choose from 11 left guys. Chance are that they will choose for either the strongest or for the kind guy. The kind guy will probably stick with them = higher chance that offspring grows up.

The strong males (who push the weak aside) will probably choose the beautiful women which probably results in strong offspring. 
The strong males also have more casual sex, which results in extra offspring.
The kind and weak guys can reach a step higher by putting in their best effort. Who will do extra good? They are not very strong, but perhaps they have other qualities: good talking, being kind, being smart. So from those groups the people with other good qualities will also have a bigger chance to reproduce with a more beautiful woman (=stronger kids in theory) or with more women (=more offspring)

And then it starts all over, but from the first generation the weak guys have hardly reproduced. The strong or the "hard working" guys did reproduce.

And if you do that experiment a million times over time the males get stronger and smarter.

And all this also apply to women, but since they get much much much fewer children the effect is much less strong. 

See, this guy, @ElKitch, knows his fewer from his less -- trust him.

There is a pretty big flaw in your model. Women outnumber men significantly. It is the women who will have to compete for the men in this scenario.

Women are subject to natural selection as well. I wrote it in the header: Natural selection: (for the example only males will get selected).But they too are subject to selection, both natural and sexual. Its just that the effect is smaller, because they reproduce at a slower rate. The strongest female still only gets 1/2 kids per year, but she probably does get them from the fittest male.

I have beaten the dead horse with the topic, but an observation I would like to note is that a lot of these obsessive, abstractly goal-seeking activities, not just chess, tend to have more males playing. For example, poker, darts, racing, video games, shred guitarists, ping pong -- something about all these things just seem to have some abstract nature to them, where you can keep practicing your technique forever and still not perfect them, making them into a sort of "endless journey"; additionally, they are satisfying only within themselves.

Personally, I find there to be a lot of things in common that the stuff I listed has, as if there is some typical mindset that makes you want to play these things that men have a higher tendency to have. And of course, gender roles could be a strong factor as well.

Sort of off to the side, does anyone else notice that everyone who plays chess seems to like tennis? (myself included) That's all I hear from chess players -- "I like to play tennis too." It's getting kind of annoying :)