Thursday, January 31, 2019

Data: The healthiest women have the fewest kids

Research shows that more than one-third of the variation in self-reported health is due to genetic differences.  Do healthy Americans have most of the kids, so future generations will trend toward good health?  The answer is, no.  Look that this graph that shows the current number of offspring for women ages 40-55 (General Social Survey, N = 965):

Women with excellent health average 2.08 children.  Those with poor health have a mean of 2.32 kids.  Now the gap is only small (one-sixth of a standard deviation), but it's enough of a difference to have an impact over the long-term.

So now we've documented negative fertility trends for IQ, education, and self-reported health. 

Liberals obsess over about how people on the bottom of society have got it so bad (they exclude poor, straight white men, of course), but in evolutionary terms, the bottom is made up of winners.


  1. There are a lot of potential confounders there... Having a child is itself a health risk, of course, as is increased age. Did your analysis include examination of those factors?

  2. Age is controlled to some extent by limiting the sample to women ages 40-55, but your point is well-taken.


Data: Are athletes smarter or dumber than others?

There are positive correlations between IQ and both longevity and height.  Many genes underlie these traits -- it looks like there are healt...