But there's also an opposing evolutionary pressure: educated women have fewer children.
The Reproduction of Intelligence attempts to quanitfy this effect:
...Although a negative relationship between fertility and education has been described consistently in most countries of the world, less is known about the relationship between intelligence and reproductive outcomes. Also the paths through which intelligence influences reproductive outcomes are uncertain. The present study uses the NLSY79 to analyze the relationship of intelligence measured in 1980 with the number of children reported in 2004, when the respondents were between 39 and 47 years
If it's worth saying, but not worth its own post, even in Discussion, it goes here.