How to Make Young Kids Smarter

In the 1920s, the Swiss psychologist Jean Piaget proposed that children’s cognitive abilities unfold naturally, like the blooming of a flower, almost independent of what else is happening in their lives. Whenever Piaget was invited to speak about his research, someone in the audience would invariably ask him what he came to call, with amusement, “the American question”—”Can we speed it up?”

hroughout the twentieth century, the debate about intelligence raged—can it be modified, how much is inherited, can we speed it up, can we even get it up to speed? In the optimistic era of the 1960s and the launch of the war on poverty, social scientists and educators developed interventions, especially for very young disadvantaged children, that they hoped would give these kids a “head start.” The nativists—who hold that intelligence is largely inherited and not amenable to intervention—were skeptical from the outset; it’s good to give poor kids breakfasts and activities, they said, but these programs will not boost IQ. The environmentalists took up the opposition, arguing that IQ can definitely be enhanced with the right kind and duration of interventions. Often these two sides used the same data to support their position: interventionists would cite a study showing cognitive gains, and the nativists would cite the same study showing that those gains were often fleeting, trivial, or illusory. 

The whole issue was being debated against the background of the Flynn effect—the fact that in developed countries IQ scores have been climbing steadily for several generations, about 3 points every decade. Since genes cannot possibly have changed enough to account for this rise, a likely reason is worldwide improvements in the education, health care, diets, and job opportunities of the poorest, lowest-scoring people, which increases the overall mean. If that is so, we would expect to see large and rapid increases in developing countries, and so we do: in Kenya, IQ scores of rural 6- to 8-year-old children jumped about 11 points between 1984 and 1998, the fastest rise in a group’s average IQ scores ever reported. Nevertheless, interventions specifically designed to raise the IQs of disadvantaged children in America have never achieved such a dramatic result, and not for want of trying. 

To try to resolve this immensely complicated issue, New York University researchers John Protzko, Joshua Aronson, and Clancy Blair created the Database of Raising Intelligence (DORI), consisting of all available high-quality experimental interventions designed to increase intelligence in young children. To be included, the study’s sample had to drawn from a general, nonclinical population rather than a special subgroup of any kind (such as children with ADHD or those with mental retardation); the study had to be based on a randomized controlled experimental design; the intervention had to have been sustained over time, rather than a one-shot “let’s try this approach;” and outcomes had to be determined by a widely accepted, standardized measure of intelligence (as opposed to academic achievement, which is influenced by many environmental factors). 

There is no magic bullet that works for all disadvantaged children, or that lasts forever, or that can reliably be exported from one setting to another.

The researchers drew a subset of 74 interventions, published and unpublished, involving nearly 40,000 young children from the prenatal period through age 5. Of these, they focused on four types of interventions that were numerous enough to permit meta-analysis. These four proved most effective in raising the IQ of young children in low socioeconomic groups: 

• Supplementing the diets of pregnant women and newborns with omega-3 fatty acids (LC-PUFA). Because earlier correlational studies had found intellectual benefits to children who were breast fed, researchers began studying the effects of supplementing baby formula with omega-3 fatty acids, which are in breast milk and essential for nerve development. And indeed, supplementing infant formula with LC-PUFA or providing it in the diets of pregnant and breast-feeding women raises a young child’s IQ by about 3.5 points. Providing preschool-aged children with iron supplements may boost their IQ, but giving iron supplements to infants does not. Other supplements—zinc, B-complex vitamins, ascorbic acid, thiamine, and multivitamins—did not show consistent IQ benefits. 
• Intense early educational interventions before entering preschool. The more complex the intervention is—the most successful ones included home visits and parent training, but programs located in specially designed child development centers were just as beneficial—the greater these gains will be, ranging from 4 to 7 IQ points. Moreover, there is no “critical period” for this intervention to be effective. The researchers found no evidence that interventions that begin in early childhood are more effective than those that begin later. The reason, they suggest, is that “the earliest few years of life are not the narrow windows of opportunity they were once thought to be.” 
• Reading interactively with children younger than age four. The sooner the interactive reading begins, the larger the benefits for the child, raising IQ by more than 6 points. Interactive reading instruction teaches parents not only to read with their children, but to do so by asking open-ended questions, encouraging their children’s participation, responding to their children’s interests in what they are reading, and so on. 
• Attending preschool. Preschool raises children’s IQ scores by more than 4 points, and more than 7 points in schools that have a specific language development component, since most intelligence tests measure information and vocabulary. 

So far, so good, but while these general findings were quite strong, they were also curiously nonspecific. There is no magic bullet that works for all disadvantaged children, or that lasts forever, or that can reliably be exported from one setting to another. Thus, specific interventions designed to improve key ingredients of intelligence—notably working memory, nonverbal reasoning, and effortful control (interventions known to help adults)—have not had much luck with children. In one intervention, researchers trained 24 four-year-olds on working memory tasks for 5 days, using a series of computer games designed to exercise various aspects of attention and inhibition. After the training, these children did not do significantly better than the control group who had not received this training. Sadly, listening to music doesn’t boost IQ either; in one study, 41 children were randomly assigned to either a phonological skills training program or a music listening program; neither intervention produced IQ gains. 

Similarly, efforts to teach mothers how to provide more “cognitively complex” environments for their children have met with mixed results. In one study, 26 mothers were randomly assigned to either a control group or an 11-week intervention during which the mothers learned to make educational materials for their children and how to help their children identify objects in the home. By the end of the study, the children of mothers in the training group had gained 7 IQ points, whereas the IQs of the control group mothers’ children remained unchanged. But other efforts to train mothers have failed to improve their children’s IQ scores, perhaps because the women did not get sufficient training and monitoring, or were not as motivated. 

One lesson is clear: within limits, IQ can be boosted.

And although going to preschool provides a significant boost to young children’s intelligence, the researchers could not say precisely why. “Because these interventions are multifaceted,” they write, “we cannot identify any particular feature of it as a causal mechanism.” The most logical reason, they suggest, is not that kids in preschool are offered some specific intervention, but that they are provided with the kind of cognitively stimulating and demanding environment that promotes intelligence. Children in preschool become exposed to new projects, ideas, and words, have a chance to solve problems, learn to navigate in new social waters, and, overall, deal with challenges they do not face at home. These challenges, the researchers suggest, increase the cognitive demands on the children, leading them to adapt and become more intelligent. 

But if preschool is beneficial because it provides a “cognitively complex” environment, it may also be the reason that its benefits wear off over time. The researchers offer the example of a physically weak child who can only do one or two push-ups. He is enrolled in a push-up intervention for six weeks, in which he does 15 push-ups per day. After six weeks, the boy can reliably do 15 push-ups. But if the intervention continues for another 12 weeks and the boy still has to do only 15 push-ups a day, he would not get stronger still. In the same way, a young child might become smarter after spending a year in preschool, but if the school’s curriculum and demands don’t change, she may not continue to be adequately challenged—and his or her intellectual progress may stagnate. 

One lesson is clear: within limits, IQ can be boosted. And creating school and home environments that foster reading, thinking, vocabulary—and, yes, music!—can only be beneficial to all children.