Britons are moving towards less educated and poorer as smart rich people have fewer children, a new study suggests.
Researchers have found that natural selection favors lower-income, less-educated people, with the next generation likely to be one or two percentage points lower in education than they are today.
Evolution also appears to benefit people at high risk for attention deficit hyperactivity disorder (ADHD), major depressive disorder and coronary artery disease, as well as younger parents and those with more sexual partners.
Prof David Hugh-Jones, principal investigator of the School of Economics at the University of East Anglia, said: “Darwin’s theory of evolution posited that all species evolve through the natural selection of small, inherited variations that affect the individual’s ability to compete. survive and reproduce.
“We wanted to know more about which traits are selected for and against in contemporary people living in the UK.”
Economic theory of fertility
The team looked at data from more than 300,000 people in the UK from the UK Biobank – a long-term project investigating the contributions of genetic predisposition and environmental exposure to disease development.
Each participant is given a polygenic score – an estimate of their genetic predisposition that roughly predicts a person’s health, education, lifestyle and personality.
They then mapped the score with their number of siblings and children across two generations to see how populations change over time.
They found that scores correlating with lower income and education were associated with having more children, meaning those people were selected from an evolutionary perspective.
In contrast, scores correlating with higher income and education were linked to having fewer children, meaning they were selected against.
Researchers said the findings were consistent with the economic theory of fertility, developed more than 60 years ago, which found that genes associated with high income predicted fewer children, because children involved greater relative wage loss.
Prof Hugh-Jones said that while the effect was small, it could grow over several generations.
“Will we all become poorer and less healthy and educated? I’d say maybe up to a point, but more research is needed,” he said.
“Remember, the environment can push the other way – in the long run, the world will become richer, better educated and healthier.
“For example, there’s the famous Flynn effect, which shows that IQs have been rising over the past few decades.”
The Flynn effect has shown that 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 educated.
“Our results suggest that natural selection makes the genetic lottery less fair,” added Professor Hugh-Jones.
Writing in the journal Behavior Genetics, the authors concluded: “Many people would probably prefer high education, low risk of ADHD and major depressive disorder, and low risk of coronary artery disease, but natural selection pushes genes into the properties.
“Possibly this could increase the health burden on modern populations, but that depends on effect sizes.”