I answered "other" because I don't know about variance, but I'm reasonably confident that even if there is a biological variance, it's not the primary reason that there's a gender imbalance in the sciences.
Coscott's question does say “in part”. (That's why I answered ‘yes’.)
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.