I wasn't being sarcastic. Studies have show diversity can trump IQ and even specialized knowledge.
Comparing diversity and IQ in general terms like that doesn't make any sense. There is no natural way to weigh IQ and diversity (Assuming you could quantify diversity satisfyingly in the first place.) when comparing the importance of them.
How many IQ points above average do you compare to adding a Hispanic woman to a group? 6.7? 12?
I googled for a study that matched your description and found "Evidence for a Collective Intelligence Factor in the Performance of Human Groups", that study didn't really show any benefit from diversity itself but rather that the"social sensitivity", something women tends to have more of than men, is the single most important factor found to predict a groups general ability to solve the tasks in this study.
They didn't find a golden ratio of men and women that worked best, so the take away message would be that men suck at working in groups.
I'm generally not that fond arguments along these lines..
Basing the desirability of women in skepticism on what would in principle be an empirical question seems really unattractive.
I think that a more reasonable way to look at it than the desirability of women in skepticism would be the desirability of skepticism in women. Would it be a good thing if more women were skeptical?