An enduring source of amusement is watching people who have a scientific perspective (and oftentimes actual training in science) throw rocks at the religious for being irrationally dogmatic.
Part of the dogma of the politically righteous today in the U.S. is that success cannot be inherited genetically. The children of the rich tend to be rich, but that is because they got cash from their parents (Exhibit A: Donald Trump!), not because they have personal characteristics that resembles their successful parents’ personal characteristics.
When this has been carefully studied, e.g., in The Son Also Rises, it turns out that success does behave like other genetically inherited characteristics. The child of successful parents has roughly the same chance of becoming successful regardless of the number of siblings who are present to dilute any financial inheritance.
She Has Her Mother’s Laugh: The Powers, Perversions, and Potential of Heredity by Carl Zimmer is a great illustration of this dogma. The book goes on at length regarding things that can be inherited genetically. But then we get an economics lesson on inequality:
Raj Chetty, a Stanford economist, has estimated that Americans born in 1940 had a 90 percent chance of making more money than their parents at age thirty. But Chetty and his colleagues have found that those odds then steadily dropped. Americans born in 1984 had only a 50 percent chance of making more than their parents. The shift was not the result of the United States suddenly running out of money. It’s just that wealthy Americans have been taking much of the extra money the economy has generated in recent decades. Chetty’s research suggests that if the recent economic growth in the United States was distributed more broadly, most of the fading he has found would disappear. “The rise in inequality and the decline in absolute mobility are closely linked,” he and his colleagues reported in 2017. Inheritance has helped push open that gulf. About two-thirds of parental income differences among Americans persist into the next generation. Economists have found that American children who are born to parents in the ninetieth percentile of earners will grow up to make three times more than children of the tenth percentile. This inheritance is not simply what parents leave in their wills but the things that they can buy for their children as they grow up. In the United States, affluent parents can afford a house in a good public school district, or even private school tuition. They can pay for college test prep classes to increase the odds their children will get into good colleges. And if they do get in, their parents can cover more of their college tuitions. Poor parents have fewer means to prepare their children to get into college. Even if their children do get accepted, they have fewer funds, and they’re more vulnerable to layoffs or medical bankruptcy. Their children may graduate saddled with steep college debts or drop out before getting a degree. The gifts that children inherit can keep coming well into adulthood. Parents may help cover the cost of law school, or write a check to help out with a septic tank that failed just after their children bought their first house. Protected from catastrophes that can wipe out bank accounts, young adults from affluent families can get started sooner on building their own wealth. Inheritance also goes a long way to explain the gap in wealth between races in the United States. In 2013, the median white American household had thirteen times the wealth of the median black household, and ten times that of the median Latino household.
Whites are five times as likely to receive major gifts from relatives, and when they do, their value is much greater. These gifts can, among other things, allow white college students to graduate with much less debt than blacks or Latinos. And the effects of these inheritances have compounded through the generations as blacks and Latinos were left outside the wealth feedback loop that benefited white families.
In looking at how the children of those in the top 10 percent do, the author does not consider the possibility that the parents reached the top 10 percent due to genetic fitness for the current economic environment. (e.g., a fondness for sitting at a desk looking at numbers on a computer screen!). So it is our cruel economic system alone that dooms children of the least successful parents to mediocre incomes. If a third generation of a family whose first and second generations were on welfare (public housing, Medicaid, food stamps, and Obamaphone) elects to continue the welfare lifestyle, this is because the parents and grandparents couldn’t provide an inheritance.
It is not the beliefs that are interesting so much as the fact that the author can’t see this dogma conflicts with all of the science that he presented in the previous pages. Perhaps the UC Davis econ professor who did The Son Also Rises got it wrong, but what’s interesting is that apparently nobody can dare to consider the possibility that he got it right.