Wednesday, September 16, 2009

Mean offspring for smart and dumb Cads

In the table, I present the mean number of children for white men ages 30-59 who have had at least 20 sex partners. I divided them into those with IQs under 100 and those above.

The terms "Alpha" and "Beta" give the former too much credit, so I'm going to use "Cads" and "Dads" instead. We saw in an earlier post that, while Dads have more kids, the gap is narrowing. The table shows that dumb Cads are contributing more kids to the current generation than their more intelligent counterpart.

The number for the dummies may be rising a bit, while falling for the smarter group, but the changes are too small to make anything of them. One factor that complicates the analysis is that small sample sizes forced me to include a wide range of ages, so the extensive overlap across decades hides trends.


Thursday said...


KingM said...

It looks like jerks of all kinds are reproducing at a lower than replacement level, which can only be a good thing.

Zephyr said...

An issue that compounds the problem is that number of children is correlated with to infant mortality: it seems people make up for the greater number of children that die in childhood by simply making more children. And child mortality is itself anticorrelated to intelligence and income.

This correlation holds internationally (countries with higher child mortality have higher birth rates per woman), but it also seems to hold in the USA: try the variables CHLDDTH(r: 0; 1-*) versus EDUC in the GSS.

Maybe there is some way you can check if dumb people still have more children after you correct for child mortality.

Zephyr said...

Here are the international statistics:

r/K selection at the national level.

Zephyr said...

And here is the international fertility rate again, this time plotted against income (proxy for intelligence), at Gapminder.