the problem with ev-psych exlanations is that they can explain anything.
Um, no. Yes it's possible to rationalize anything if one is creative enough, this isn't limited to ev-psych, but just as some arguments are better then others, some ev-psych explanations are better then others, and this one is pretty straightforward: namely since the number of children an individual female can have is much more limited then an individual male, it makes sense for females to use less risky, i.e., lower variance, strategies. Hence, we should expect males to have a higher variance in most traits unless there is some reason for that particular trait to be selected otherwise.
Being able to offer a mechanism is, in my view, rather important for corroboration.
Um, in fact in this case a single mechanism would be evidence against the ev-psych explanation, which predicts evolution to arrange this for each trait in whatever way it happens to stumble upon.
some ev-psych explanations are better then others
That may or may not be so, but ev-psych explanations are no more than post factum just-so stories, nothing but handwaving. They are useful to humans because humans have a need to have things explained, but they are not science.
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.