What Makes Kids Intelligent?

Raising Smart Kids

Medically Reviewed by Charlotte E. Grayson Mathis, MD
6 min read

Oct. 15, 2001 -- How can we make our children smarter?

A tough question, since some kids are book smart while others are street smart. Some build towering block skyscrapers while others paint word pictures in poetry and prose. Some win the school election while others know just what to say to make you feel better.

"Intelligence reflects the general ability to process information, which promotes learning, understanding, reasoning, [and] problem-solving," says Linda S. Gottfredson, PhD, a professor of education at the University of Delaware in Newark. "It affects many sorts of everyday behaviors."

As each child is unique, we'll focus on why children differ in intelligence, and on how to bring out their best.

Heredity accounts for more than 80% of the variation in adult intelligence, yet each successive generation appears smarter on IQ tests, highlighting the importance of environmental factors. Why the apparent contradiction?

"The hidden assumption in this paradox is that genes and environment are unrelated, which sounds ridiculous as soon as you say it," William T. Dickens, PhD, a senior fellow in economic studies at Brookings Institute in Washington, D.C., tells WebMD. "Genes get the credit for most of the work that the environment is doing."

Where intelligence is concerned, the rich get richer and the poor get poorer. Children born with higher intelligence do better in school, which enables them to get into enriched classes or go to college where they further their intelligence.

"If the environment affects IQ and the IQ affects environment, it's a virtuous or vicious cycle," Dickens says.

Over time, the effects of the environment on intelligence get weaker. For example, after a child enters a preschool enrichment program, IQ peaks within six to 12 months. When the child leaves that environment, IQ drifts downward.

"When you remove a kid from a good environment and put him back in a bad one, he'll do different things than he did before," Dickens says. "He may choose brighter friends or watch more educational TV shows. But there are fewer options than in the good environment, so, over time, there'll be a slow drag on his IQ."

How much stock should we put in those magical IQ numbers?

"I don't think there is much point in trying to assess children's intelligence unless they seem unusual -- not developing properly or precocious," Gottfredson says. "People tend to take individual test scores too seriously."

"A better indicator than IQ score is whether the child is curious, enjoys role playing and learning, and is happy," says Stephen J. Schoenthaler, PhD, a professor of nutrition and behavior at California State University in Long Beach.

But Dickens contends that the one thing that best predicts how well 14-year-olds will do as adults, in terms of economic and social outcome, is their IQ score.

Eating smarter for better brain health begins in the womb and continues with breastfeeding, especially if Mom follows daily recommendations for vitamins and minerals.

"The real trick is teaching young children to like good foods when they move from breast milk to whole foods," Schoenthaler tells WebMD. "Teaching children to try everything and then avoid foods they do not like for a year or so as taste develops works fine."

Children need five or six daily servings of fruits and vegetables; five servings of whole grains; two or three servings of meat, fish, or poultry; and two or three servings of milk. Smaller-than-adult-size portions will keep children from gaining too much weight. As young children prefer salty and sweet tastes, mothers can "spice up" vegetables sparingly. Children should take a vitamin and mineral supplement at the prescribed dose.

"What the Food and Nutrition Board and the World Health Organization recommend for good health is great for IQ and behavior too," Schoenthaler says.

In his research, children taking the recommended daily allowance of vitamin and mineral supplements for three months learned 14 different academic subjects at twice the rate of children given a placebo. In more than 1 million children given a good breakfast and lunch at school, academic performance improved by 16%, and 76,000 suddenly were no longer "learning disabled."

"To train young minds, read something together every night. Stimulate your child's interests and curiosity and encourage the child to play an instrument," Ingegerd Carlsson, PhD, tells WebMD. She is a psychologist at Lund University in Sweden, and studies changes in brain function with creativity.

However, the "Mozart effect," in which listening to classical music supposedly improves certain IQ scores, is probably overrated, says Kenneth M. Steele, PhD, associate professor of psychology at Appalachian State University in Boone, N.C.

"Infants, toddlers, and preschoolers who grow up in homes where talking, listening, and reading are common tend to have higher IQs and greater success in school," Frances P. Glascoe, PhD, an adjunct professor of pediatrics at Vanderbilt University in East Berlin, Pa., tells WebMD.

Thomas Darvill, PhD, chairman of psychology at Oswego State University in New York, recommends a variety of safe toys that are colorful, noisy, and interesting in shape or texture. Spending more time with your child in their first year can yield big dividends later, both in terms of parent-child bonding and enhanced mental growth.

"Kids left alone to sit and watch TV or play video games on their own won't do as well," Shawn K. Acheson, PhD, assistant professor of psychology at Western Carolina University in Cullowhee, N.C., tells WebMD. "Encourage active learning and the exchange of ideas."

As they grow, children need time and freedom to play and explore, Darvill says. "If your preschooler is playing in the mud or role playing with you or a peer, he is learning what he needs to learn."

Sports, music, and other activities demanding focused attention and discipline and stimulate mental development -- but don't force children to adopt your own interests. "Just because Dad enjoyed hockey as a child doesn't guarantee that his own children will," Darvill says.

Each child's interests and learning strategies are unique, Gottfredson agrees. To develop intelligence, we must not neglect ambition, courage, and conscientiousness, which are equally important for success. We mustn't forget to teach children how to learn.

"Few people work to their potential, or even realize what it is," she says. "Encourage children to develop the attitudes and tools for making the best use of their minds."

Robert J. Sternberg, PhD, is director of the PACE Center and IBM professor of psychology and education at Yale University. "If we take into account how children think, we can improve their achievement," Sternberg tells WebMD. "If we teach in a way that is relevant to children's abilities, we get much better results."

As early environmental effects wear off, intelligence training should be a lifelong pursuit. Nourished by a healthy diet and encouraged to use their unique gifts most effectively, your child should be off to a running start.

"If you can accelerate children's ability to learn -- even temporarily -- the knowledge they've acquired may still be with them 20 or 30 years later," Dickens says. "Some skills stay with you your whole life. Parents can permanently affect their child's job success and income, even if they can't permanently change his IQ."

According to the "Flynn effect" discovered by James R. Flynn, PhD, a political scientist at the University of Otago in New Zealand, the average IQ for the population as a whole increases with each generation. He tells WebMD that the best gift you can give your child is a love for learning and for satisfying work.

"If you do that for your child, for heaven's sake don't worry about IQ," Flynn says. "They have got what makes life rewarding anyway."