She Has Her Mother's Laugh: The Powers, Perversions, and Potential of Heredity (43 page)

When Galton and Pearson investigated the inheritance of height, they presented their results in cool prose, letting the statistics speak for themselves. When they turned their attention to intelligence, however, their lectures and papers became sermons. Galton promised a galaxy of genius through eugenics. Pearson, writing in 1904, drew a darker conclusion. “
For the last forty years,” he warned, “the intellectual classes of the nation, enervated by wealth or by love of pleasure, or following an erroneous standard of life, have ceased to give us in due proportion the men we want to carry on the ever-growing work of our empire.”

American eugenicists saw the same moral contrast between height and intelligence. They didn't see any need to promote the height of the nation. But to protect American intelligence from feeblemindedness, they were ready to sterilize, to institutionalize, to bar immigrants.

Nazis made much of intelligence as well, their hereditary courts making their decisions based on test scores. Yet those scores had to fit into Nazism's racist ideology, not vice versa.

When
German psychiatrists called for the sterilization of even the mildly feebleminded, their proposal was shot down. Many of Hitler's young Brownshirts would have fallen into that category—not to mention 10 percent of the German army. Friedrich Bartels, the deputy leader of the Reich doctors, rejected intelligence tests because they could condemn decent young German peasants. He said it was wrong to judge the value of a Nazi Party member based on how much trivia they knew, such as the year Columbus was born. Such a man might very well have spent his life until then working in the fields rather than taking classes. “
It is quite possible that he has never had the chance to learn these things,” Bartels complained.

As early as the 1920s, some psychologists were challenging the fatalism of people like Galton and Pearson.
Helen Barrett and Helen Koch of the University of Chicago studied a group of children who were moved from an orphanage into preschool, where they were no longer neglected. After six months, Barrett and Koch claimed, their test scores jumped far beyond those of the children left behind in the orphanage. Intelligence was not simply the result of heredity, they argued, but also the quality of homes and schools.

In the 1930s, psychologists in Iowa ran a bigger study that came to a similar conclusion. In 1938, one of the researchers, George Stoddard, went to a conference in New York to describe the results, and a reporter from
Time
delivered the astonishing news. “
One of the few fixed stars in the creed of orthodox psychologists is a belief that people are born with a certain degree of intelligence and are doomed to go through life with the same I.Q.,” the
Time
reporter explained. But Stoddard—“moonfaced, enthusiastic”—proved “that an individual's I.Q. can be changed.”

Stoddard and his team tracked 275 children who were put into foster care. Their parents were poor, badly educated, and scored below average on intelligence tests. After being placed “in better than average homes,”
Time
reported, they scored an average IQ of 116—“equal to the average for children of university professors.”

The Iowa studies led Stoddard to reject the eugenicist claim that heredity trumped all. “Dull parents are as likely to produce potentially bright children as are clever parents,” Stoddard declared. “The way to improve a child's intelligence is to give him security, encourage him in habits of experiencing, inquiring, relating, symbolizing.”

Hereditarians attacked Stoddard's work, pointing out its many statistical weaknesses. His critics maintained that intelligence tests measured something fixed in people, and Stoddard's calls for a national network of preschools went ignored. When
World War II came, it focused the country's attention abroad, and the prosperity of the 1950s left many Americans unaware of the poverty that others endured in the country.

After World War II, most Americans no longer followed Lewis Terman's
example, claiming that Southern and Eastern Europeans inherited low intelligence. But some still maintained that heredity was to blame for the gap between whites and blacks. Henry Garrett, the prominent psychologist who kept the Kallikaks alive in his textbooks, claimed that blacks were as intelligent on average as a
white person after a lobotomy.

Garrett was an ardent supporter of segregation, and he brought his considerable credentials—former president of the American Psychological Association and professor at Columbia University—to the fight against racial equality. He served as a star witness for the segregationist defense in
Brown v. Board of Education
and acted as an FBI informant,
reporting on the “Communistic theories” his fellow Columbia University professors were spreading about the equality of the races.

In 1955, Garrett retired from Columbia and moved back to the South to fight full-time. He testified to Congress in 1967 against a civil rights bill, lecturing the politicians about the evolutionary “immaturity” of the Negro. He became a director of the Pioneer Fund, a eugenics organization founded in 1937 to promote “the conservation of the best racial stocks.” Garrett also became a prolific pamphleteer. Pro-segregation groups distributed over half a million of his pamphlets to American public school teachers, free of charge. Today, neo-Nazi groups continue to sell them.

In his pamphlets, Garrett railed against mixing blacks and whites—both in schools and in marriages. Such a disaster would drag down Western civilization, he warned. Pointing to studies that showed a 15- to 20-point gap between American whites and blacks on IQ tests, Garrett claimed that the differences were fixed by heredity. The notion that blacks and whites were equal was, Garrett declared, “
the scientific hoax of the century.” He pinned the blame for the hoax, unsurprisingly, on the Jews.

Garrett faced stiff opposition from many of his fellow American psychologists. They argued that poverty had a tremendous power over young minds. Experiments on animals were revealing just how crucial experiences could be to the early development of the brain. If kittens had their eyes sewn shut for just a few crucial days, they were left blind for the rest of their lives. A growing number of psychologists argued that children had a
crucial window in their own development. If their early years were deprived, their intelligence would suffer just as their growth would be stunted. In 1965, Lyndon Johnson launched the preschool network that the Iowa psychologists had called for three decades earlier. The Head Start program began enrolling hundreds of thousands of poor children.

Robert E. Cooke, a Johns Hopkins pediatrician and the chair of Head Start's original planning committee, would later describe the program as a rejection of heredity's power. “
The fundamental theoretical basis of Head Start was the concept that intellect is, to a large extent, a product of experience, not inheritance,” he said.

In later years, social scientists would document
many benefits to the Head Start program. It raised the graduation rate of children by more than 5 percent, for instance; among children with mothers who didn't finish high school, the rate rose by more than 10 percent. But it did not help children's intelligence test scores in the long run. At three and four years of age, their scores improved,
only to drift back down by first grade.

Critics jumped on these findings as evidence that blacks scored lower than whites on intelligence tests due to their genes. In a 1967 lecture,
an educational psychologist named Arthur Jensen declared that the lower average scores that blacks got on intelligence tests “do indeed reflect innate, genetically determined aspects of intellectual ability.” In the decades since, others have made similar claims from time to time. For the most part, though, psychologists and geneticists alike
have rejected them. It's clear that intelligence test scores are heritable. But just because two groups differ in a heritable trait does not mean that the difference between them is genetic.

The study of height provides a clear and uncontroversial demonstration of this rule. South Koreans are more than an inch taller on average than North Koreans. Height is even more heritable than intelligence. But these two facts don't add up to the conclusion that South Koreans have height-boosting alleles that are missing from North Koreans. In fact, we can be pretty confident they don't. Koreans only became two groups in the 1950s. Only afterward, as South Korea prospered and North Korea fell into the twilight of dictatorship, did their heights diverge.

Nor does the failure of Head Start serve as proof that the 1960s gap in intelligence test scores was some unalterable fact of heredity.
The Flynn effect did not leave behind American blacks, for example. In fact, their intelligence test scores have risen dramatically, while American whites had a more modest improvement. The gap between the two groups narrowed by more than 40 percent between 1980 and 2012, according to one estimate.

Studies like these have led some critics to argue that research on the hereditary basis of intelligence is irrelevant at best and toxic at worst. If our goal is to improve the intellect of children, then we have plenty of obvious—but hard—work to do. We should fix the fumbling bureaucracies that run schools, stop programs that don't work, put ones into effect that do, and fix the causes of inequalities in education. We can also look beyond schools, to take on the harmful stress of poverty or the continuing threat of lead in drinking water. “Such efforts need no genetic information—or even I.Q. testing—and are likely to be hindered by the hereditary concept of intelligence,” writes
Dorothy Roberts, a University of Pennsylvania law professor.

Geneticists have fought back, calling these attacks caricatures of the modern study of intelligence. They are not using weak science to justify the status quo, or to argue for the superiority of one race over another. Nor are they claiming that because a trait is heritable means that interventions are pointless. Some point to the case of eyesight as an analogy. Eyesight is a strongly heritable trait, and yet eyeglasses can overcome the bad vision that children inherit from their parents. It would be absurd to say that there's no point trying to improve bad eyesight, since it's heritable.

In fact, some geneticists argue, understanding how heredity influences intelligence may potentially lead to policies that do a better job of helping children flourish.
When education researchers test out new programs, they compare how well students do with it or without. In order for those studies to yield reliable results, the researchers have to make sure the two groups are random samples of students. If one group just so happens to have a lot of the variants known to influence intelligence or educational attainment, the study may deceive the researchers. They may come to believe a program
is going to have a powerful effect, only to find out too late that it's just a waste of time and money.

Some researchers have gone further and predicted that DNA scans will make it possible to
tailor school programs to each child. Genetic tests can already reveal some severe forms of intellectual disability in newborns and, in some cases, that knowledge is power. A child diagnosed today with PKU doesn't have to face Carol Buck's fate. By inspecting thousands of intelligence-related spots in the DNA of children, it might be possible to make predictions about how they will fare in school. Some variants might turn out to influence
g,
influencing overall intelligence, while others might affect only certain mental abilities. Kathryn Asbury, a lecturer at the University of York, has argued that these genetic tests might allow parents to intervene early with children who are, for example, dyslexic. “
If a simple blood test at birth could spot children with a probable risk of struggling in any of these areas,” she says, “then imagine the tailored interventions that might nip such risk in the bud or at least reduce its effects.”

“
Precision education,” as this approach has been called, has a sleek, futuristic appeal. But for now, and probably for decades,
it's only a placeholder of an idea. In the meantime, less sexy tasks will help children more, such as getting the lead out of drinking water in schools and getting enough textbooks for students. Instead of providing concrete help, research on heredity may end up fueling fallacies about the nature of intelligence. Unfortunately, psychologists have found, our minds have vulnerabilities when it comes to such matters. There's a reason that
The Kallikak Family—
with its simplistic, destructive vision of heredity and society—sold as well as it did.

In 2011 the psychologists Ilan Dar-Nimrod and Steven Heine
dubbed this kind of thinking “genetic essentialism.” Dar-Nimrod and Heine argued that genetic essentialism arises from how we make sense of the world. Decades of psychological research have shown that
our minds instinctively sort things into categories. We ascribe the same essence to everything in the same category. Birds all have birdiness, and fish have fishiness. When psychologists try to get people to describe these essences, words often fail
them. Feathers are a manifestation of birdiness, but if a bird gets sick and loses its feathers, we still consider it a bird. We use essentialism to make sense not just of birds but of each other as well. Early in childhood, we learn to view people as having essential characteristics, which we perceive as being present at birth and enduring throughout life.

Our built-in essentialism made it easy for us to misunderstand heredity. Genes seem like they belong to our essence. We inherit them from our parents and carry them till we die. It's tempting to conclude that
nothing we do in our lives can change what our genes bring about. We are successful because we have genes for success. Races are different because the people in each race share genes not found in any other race.

Genetic essentialism turns out to be stronger in some people than in others. In one study, psychologists measured people's racism by asking them questions such as whether they'd approve of their child marrying a black partner or whether they think blacks have only themselves to blame for not doing well. It turns out that people who ascribe more of the differences between races to genes score higher on tests of racism.