Why does egalitarian society has a lower density of men in the community?

I could explain the opposite claim: a non-egalitarian society typically has a higher density of men. This is caused by the regular killing of female babies: when a family can afford only one child, they would choose to raise only a boy.

In an egalitarian society this is not the case, and hence female children are not killed (any more then male chilredn) - so it would have a higher density of men.

The details that best show evidence of tribal traditions are, "never in the history of his people had a man married a woman who spoke a different tongue” and "it has never been heard," was the verdict of an old man speaking a few weeks later.