On point 2, again, the reason women are thought to vary less than men is that they have two copies of the x chromosome.
The reason women are thought to vary less than men is because that's what nearly all the statistics say. There is a fairly straightforward ev-psych explanation for this. As for the mechanism, there is no consensus on it and it's not at all clear that the mechanism you describe is the only (or even main) one.
The reason women are thought to vary less than men is because that's what nearly all the statistics say.
The only statistics I've actually seen addressing sex differences in standard deviations from the mean are IQ, height, weight, and life expectancy. Do you have links to studies from this perspective on other traits?
There is a fairly straightforward ev-psych explanation for this.
Without disputing the fact that evolutionary psychology may correctly explain some things, the problem with ev-psych exlanations is that they can explain anything. Just...
This is an experiment to use polls to tap into the crowd knowledge probably present on LW.
This is your chance to ask your multiple choice question you always wanted to throw in. Get qualified numeric feedback to your comments. Post fun polls.
There are some rules:
If you don't know how to make a poll in a comment look at the Poll Markup Help.
This being an experiment I do not announce it to be regular. If it is successful I may. Or you may. In that case I recommend the following to make this potentially more usable:
EDIT: Added recommendations from KnaveOfAllTrades.