Britons are evolving to be less well-educated and poorer because smart rich people are having fewer children, a new study has suggested.
Researchers have found that natural selection is favoring people with lower earnings and poorer education, with the next generation likely to be one or two percentage points lower in educational attainment than today.
Evolution also appears to be favoring people with a high risk of Attention Deficit Hyperactivity Disorder (ADHD), major depressive disorders and coronary artery disease, as well as younger parents and people with more sexual partners.
Prof David Hugh-Jones, lead researcher from University of East Anglia’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 UK.”
Economic theory of fertility
The team looked at data from more than 300,000 people in the UK, taken from the UK Biobank – a long-term project investigating the contributions of genetic predisposition and environmental exposure to the development of disease.
Each participant is given a polygenic score – an estimate of their genetic liability that roughly predicts a person’s health, education, lifestyle and personality.
They then mapped the score to their number of siblings and children over two generations to see how the populations are changing over time.
They found that scores correlating with lower earnings and education were linked to having more children, meaning those people were being selected from an evolutionary perspective.
In contrast, scores that correlated with higher earnings and education were linked to having fewer children, meaning that they are being selected against.
Researchers said the findings corresponded to the economic theory of fertility, which was developed more than 60 years ago and which found genes linked to high earnings predicted fewer children, because children brought a bigger relative loss of wages.
Prof Hugh-Jones said that although the effect was small, it could grow over multiple generations.
“Will we all become poorer and less healthy and educated? I’d say maybe to a degree, but more research is needed,” he said.
“Remember that the environment may be pushing the other way – in the long run, the world is getting richer and better educated and healthier.
“For example there’s the famous Flynn effect, which shows IQs going up over the past few decades.”
The Flynn effect has shown there has been a continuous and linear growth in intelligence since IQ was first measured. For example, between 1942 and 2008, the average British child’s IQ score rose by 14 points.
But researchers said their findings showed that society could become more unequal in the future, with more people on low incomes and less well educated.
“Our results suggest that natural selection is making the genetic lottery less fair,” added Prof Hugh-Jones.
Writing in the journal Behavior Genetics, the authors concluded: “Many people would probably prefer to have high educational attainment, a low risk of ADHD and major depressive disorder, and a low risk of coronary artery disease, but natural selection is pushing against genes associated with these features.
“Potentially, this could increase the health burden on modern populations, but that depends on effect sizes.”