"Who's having the babies"

This was an interesting article. The author starts out by noting a recent study on parenting in Norway which concluded that "a fifth to a quarter of men from the Boom generation and the generation following had no children," a figure which apparently matched that from the author's similar research in the US.

Later he crunches some more number, looking at factors like IQ and political affiliation:

He crunched some more numbers: "fertility is dysgenic for women and roughly neutral for men by IQ. However, here we see that there is finer pattern behind this when you break it down. What is actually happening is that fertility is highly dysgenic by IQ for liberal men (for whom indeed, the smartest category of such men here – roughly IQ 115+ – about 50% leave no descendants); is slightly dysgenic for moderate men; and is slightly eugenic for conservative men.

I wonder how much of a hidden factor religious affiliation might be in explaining the differences between liberal and conservatives. It's also interesting that amongst liberals those with the highest IQs seem the most likely to be childless. The Atlantic had a recent article about childless female academics but it seems that similar figures apply to men as well.