Tabarrok nails it.
Agnostic adds: Here’s a graph using the new study’s finding of same mean for males and females, and taking male to female ratio in variances to be 1.16 (they estimate it between 1.11 and 1.21). This is the ratio of a normal with mean = 0 and s.d. = 1.077 (male) to a standard normal (female). It’s shown for above-average people, but it’s symmetric about 0: males have more geniuses and more idiots. The dashed green line is M:F = 1, or perfect gender parity. Males are underrepresented between -1 and +1 s.d., and overrepresented outside this interval. You may have to click on the image to see it full-size.
Labels: sex differences