From Phys.Org, a website that posts universities’ press releases about their professors’ research (not that that’s a bad thing: colleges employ talented journalists to make their researchers sound comprehensible, plus the college PR staffers check with the professors to see if they got it right before posting):
JULY 6, 2022
Natural selection may be making society more unequal
by University of East Anglia
Contemporary humans are still evolving, but natural selection favors those with lower earnings and poorer education—according to research from the University of East Anglia.
A new study published today shows how natural selection effects are stronger in groups with lower income and less education, among younger parents, people not living with a partner, and people with more lifetime sexual partners.
Meanwhile, natural selection is pushing against genes associated with high educational attainment, high earnings, a low risk of ADHD or major depressive disorder, and a low risk of coronary artery disease.
Lead researcher Prof. David Hugh-Jones, from UEA’s School of Economics, said: “Darwin’s theory of evolution stated that all species develop through the natural selection of small, inherited variations that increase the individual’s ability to compete, survive, and reproduce.
“We wanted to find out more about which characteristics are selected for and against in contemporary humans, living in the U.K.”
The research team looked at data from more than 300,000 people in the U.K., taken from the U.K. Biobank—a long-term project investigating the respective contributions of genetic predisposition and environmental exposure to the development of disease.
The study only looked at white people.
The team studied the participants’ polygenic scores—an estimate of a person’s genetic liability, predicting a person’s health, education, lifestyle or personality.
They looked at two generations of people living in the U.K., by using data on the participants’ number of siblings as well as their number of children.
David Hugh-Jones said: “We found that 23 out of 33 polygenic scores were significantly linked to a person having more or fewer children over their lifetime.
“Scores which correlated with lower earnings and education predicted having more children, meaning those scores are being selected for from an evolutionary perspective.
“Scores which correlated with higher earnings and education predicted having fewer children, meaning that they are being selected against.
“The effects were especially strong among people with less education and lower incomes, and among people not living with a partner. Among older mothers, effects were actually reversed—in this group, scores correlating with higher earnings were selected for.
One interesting question is whether the sharp dysgenic effect seen for the two measures of educational attainment compared to the modest dysgenic effect seen for cognitive ability is real or due to the more well-developed polygenic scores data (James J. Lee, et al.) for educational attainment compared to cognitive ability. Lee has assembled three million genomes for which educational attainment (e.g., “some college”) has been checked off on a box. In contrast, actual IQ tests are rapidly accumulating, but they tend to come it at about 10,000 at a time due to massively expensive longitudinal studies, such as the ABCD. Maybe if we had the DNA of 3 million people for whom we had IQ scores, the dysgenic effect would be as steep?
Or it could be that educational attainment is a test of both cognitive ability and socialization and picks for meeker males?
It’s long been recognized that more educated women tend to have fewer children, which, all else being equal, would lead to dysgenics.
On the other hand, more intelligent men tend to be able to afford more wives. I wouldn’t be surprised if guys who had a lot on the ball but didn’t have the patience to stick out college but then made a lot of money anyway tend to be the kind of guys who wind up paying alimony for a lot of wives and kids.
We explain these patterns using the economic theory of fertility, which was first developed more than 60 years ago.
Gary Becker said that higher income could either increase fertility by making more children affordable or decrease fertility by making the opportunity cost of kids higher. Thanks, Gary, that clears everything up!
… Natural selection could be making society more unequal, by increasing the correlation between income and polygenic scores, including scores that predict health and educational outcomes.
In any case, that seems pretty inevitable: natural selection making society more unequal.