From what I understand, the studies show that men's and women's IQ distributions have the same average, but men's IQs have a higher standard deviation. Or, there's more men with really high and really low IQs than women, but the average works out about the same. Hence, you'll see more men as nobel prize winners, but if you take the 100 dumbest people you can find, there's probably only going to be a handful of women in that group. Mostly men.
Of course, that's just one measure of intelligence. True intelligence has to be developed and trained, and most of us (all of us?) live in a culture where men are seen as the hard worker, bread winner, physical labor types. There's tons of bright young men who are dropping out early to go to work to feed their families. These are dudes who, with the proper training, could perhaps be brought to produce a genius level body of work, but instead they're fixing cars or chopping wood or what have you.
That's a bit focused on the extremes, though. For the vast majority of people sitting in the middle, where I think most of us are, there's really not much point to trying to figure out who's smarter or not. The only real difference is going to be our past experience with whatever task comes up. The computerization of every facet of life makes that type of knowledge especially useful.
