Intelligence in children: Can we make our kids smarter?

© 2008-2013 Gwen Dewar, Ph.D., all rights reserved

Intelligence-boosting products are big business: Books, toys, DVDs, software, games, and educational programs designed to make your child into an intellectual prodigy.

Many of these products come with claims–explicit or implicit–that their usefulness is supported by scientific evidence. Are they really?

Sometimes. For instance, as I’ve noted elsewhere, there is evidence that

But many “brainy” products are ineffective. For example, a controlled experiment has failed to show that infants learn to read from media-based instructional programs (Neuman et al 2014). And the evidence suggests that very young children don’t learn to talk by watching educational videos. Instead, babies learn language by listening to and interacting with live human beings (Kuhl 2005).

Then there are misconceptions and folk beliefs, like the idea that praising children for their intelligence will raise self-esteem and improve their academic performance.

An impressive series of experiments suggests that the opposite is true. Praising kids for being smart tends to make them act dumb.

Even more interesting–at least to me–is the discovery that our beliefs about intelligence can hamper the learning process. People who are convinced that intelligence is a fixed, unchanging trait are less likely to learn from their mistakes and less likely to succeed in school.

Moreover, experiments suggest that your child’s awareness of social stereotypes about intelligence and achievement (e.g., “girls have stronger language skills,” or “Asian kids are math prodigies”) can undermine his or her academic performance.

So here I present my guide to the “good bets”—evidence-based information about the ways that parents can nurture their children’s intelligence. I will be adding more articles over time.

Exercise and intelligence

It’s both intriguing and unexpected: Aerobic exercise stimulates brain growth and enhances our ability to learn. Studies also suggest that exercise can help kids focus attention in school. But there’s a catch: To reap full benefits, exercise must be voluntary. Click here for the whole story.


Free play promotes better learning, memory, and growth of the cerebral cortex. It also enhances the development of language, spatial intelligence, counterfactual reasoning, and mathematical skills. For more information, see this article about the cognitive benefits of play.

Working memory: The new IQ?

New research indicates that working memory capacity–that mental notepad that we use to think thoughts and solve problems–is a better predictor of school achievement than IQ. Read more about working memory and the ways we can help children cope with limitations in working memory capacity.


There’s also good evidence that gesturing with your hands improves your ability to remember and learn. Cognitive psychologist Susan Goldin-Meadow and her colleagues have conducted a series of experiments showing that kids are more likely to remember words, events, and even math lessons when they gesture with their hands.

For the details, see this article on the science of gestures.

Parental sensitivity, attachment security, and intelligence

Researchers have noted a correlation between child IQ scores and attachment status. For instance, one study of 36 middle-class mothers and their three-year-olds found that securely-attached children scored 12 points higher on the Stanford-Binet intelligence test than did insecurely attached children (Crandell and Hobson 1999).

What’s responsible for this correlation? It’s possible that more intelligent children have an easier time forming secure attachments. For instance, more intelligent kids are probably better at interpreting their parents’ behavior and selecting the most appropriate response (Waters and Valenzuela 1999).

But there is also evidence suggesting that responsive parenting—which promotes secure attachments—contributes to higher cognitive ability.

In experiments with families at high risk for poor child outcomes, researchers randomly assigned some mothers to receive training in responsive parenting techniques. The infants of trained mothers showed greater growth in cognitive skills than did the infants of control moms (Landry et al 2003; 2006).

The results are consistent with a recent study that attributes the cognitive advantages of breastfed babies to sensitive, responsive parenting (Gibbs and Forste 2014).

Mindsets for failure: Beliefs that hold your child back

Does your child believe that intelligence is a fixed trait?

Fascinating experiments indicate that what we believe about intelligence can impede our ability to learn.

People who believe that intelligence is a fixed, stable trait are more likely to avoid challenges. They are also less likely to learn from their mistakes–and the difference shows up in bran scans. Read more about this phenomenon and how it affects kids.

Does your child believe that “people like me” don’t do well academically?

If so, her beliefs might be undermining her performance in school. Sound like politically correct propaganda? There is actually a lot of solid experimental evidence confirming the existence of “stereotype threat.” Learn more about this research and what you can do to counteract its effects.

How praise can undermine your child’s capacity to learn

Praise can be a great motivator. But it can also make kids focus on the wrong goals. Research shows that the wrong kinds of praise can actually undermine motivation and leave kids feeling helpless when they fail. For more information, see this article about the perils of praising kids for being smart.

Sleep and intelligence

Sleep and learning

There is a convincing body of evidence to suggest that we are more likely to retain what we’ve learned-and more likely to achieve new insights—if we go to sleep shortly after our studies (Gais et al 2006; Wagner et al 2004).

People don’t need to sleep all night for the effect to work. Naps as short as 60 minutes may be just as effective, as long as they include slow-wave (non-REM) sleep (Mednick et al 2003; Alger et al 2012).

The effect has been demonstrated on kids as well as adults (Backhaus et al 2008; Kurdziel et al 2013). So it seems to make sense for kids to schedule their studies before naps and bedtime.

Unfortunately, institutionalized learning doesn’t make room for study-naps! It would appear that home-schoolers, and other kids with flexible academic schedules, are at a distinct advantage.

Sleep and cognitive development

It’s also possible that chronic sleep restriction has a lasting effect on cognitive performance.

In a study tracking Canadian kids from age 2.5 to 6 years, researchers found that kids who were poor sleepers as toddlers performed more poorly on neurodevelopmental tests when they were 6 years old (Touchette et al 2007).

This was true even for kids whose sleep improved after age 3. The researchers speculate that there may be a “critical period” in early childhood, when the effects of sleep restriction are especially harmful (Touchette et al 2007).

Math, logic, and critical thinking

Stanislaus Dehaene is a cognitive scientist and expert on the mathematical brain.

He argues that many kids have poor math skills because they are discouraged from developing an intuitive sense of number.

For more information, check out this article about number sense.

In addition, see this article about the way that some board games can help preschoolers develop their math skills.

And what about logic? Experimental studies suggest that explicit instruction in critical thinking–including lessons in basic logic, hypothesis testing, and scientific reasoning–can raise a child’s IQ.

Unfortunately, such lessons are not yet a common part of most high school–let alone middle school curricula. Even worse, I suspect that the media and other influences are training our kids to think with blinders on. To see what I mean, read this article on critical thinking in children.

How can we support the development of critical thinking? See my article, “Teaching critical thinking: The first step is to pause and reflect.”

Spatial intelligence

Spatial skills are crucial for success in a variety of fields, ranging from physics and engineering to architecture and the visual arts. Your child’s performance on spatial tasks has a hereditary component, but it’s clear that educational experiences can also have a big impact.

Read more about it in my evidence-based overview, “Spatial intelligence in children: Why training matters.”

And for research-based activities that may boost your child’s spatial skills, see this article.

Free choice

Kids show greater motivation and perform better when they get to choose what they do (Iyengar and Lepper 1999).

Well—that’s true for some American kids, anyway. It turns out that the effect is culture-specific. One study compared Anglo-American and Asian American kids. While the Anglo-Americans preferred tasks they had chosen for themselves, the Asian Americans showed more motivation when their choices were made for them by trusted authority figures or peers (Iyengar and Lepper 1999).

The upshot? There may be no “one size fits all” approach to classroom learning. Some kids may thrive when teachers give them choices. Others might find this approach to be disconcerting.

Toys and games that boost cognitive skills

Although there is evidence that action video games improve spatial skills and may even help dyslexic children learn to read, some of the most important developmental toys and games are the most old-fashioned.

For instance, research suggests that toy blocks may enhance spatial, math, problem-solving, and verbal skills. Find evidence-based information about blocks and other toys in these Parenting Science pages.

References: Nurturing intelligence and promoting achievement in kids

Alger SE, Lau H, and Fishbein W. 2012. Slow wave sleep during a daytime nap is necessary for protection from subsequent interference and long-term retention. Neurobiol Learn Mem. 98(2):188-96.

Backhaus J, Hoeckesfeld R, Born J, and Jung. 2008. Immediate as well as delayed post learning sleep but not wakefulness enhances declarative memory consolidation in children. Neurobiol Learn Mem 89(1): 76-80.

Crandell LE and Hobson RP. 1999. Individual differences in young children’s IQ: a social-developmental perspective. J Child Psychol Psychiatry. 40(3):455-64.

Gais S, Lucas B, and Born J. 2006. Sleep after learning aids memory recall. Learning and Memory 13: 259-262.

Iyengar SS and Lepper MR. 1999. Rethinking the value of choice: a cultural perspective on intrinsic motivation. J Pers Soc Psychol. 76(3):349-66.

Just MA and Carpenter PA. 1987. The psychology of reading and language comprehension. Boston: Allyn and Bacon.

Kuhl PK. 2005. Early language acquisition: Cracking the speech code. Nature Neuroscience 5: 831-843.

Kurdziel L, Duclos K, and Spencer R. 2013. Sleep spindles in midday naps enhance learning in preschool children. PNAS (epub ahead of print) doi: 10.1073/pnas.1306418110.

Mednick S, Nakayama K and Stickgold R. 2003. Sleep-dependent learning: A nap is as good as a night. Nature Neuroscience 6(7); 697-698.

Neuman SB, Kaefer T, Pinkham A, and Strouse G. 2014. Can Babies Learn to Read? A Randomized Trial of Baby Media.Journal of Educational Psychology DOI: 10.1037/a0035937.

Rayner K. 1998. Eye movements in reading and information processing: 20 years of research. Psychological Bulletin 124(3): 372-422.

Touchette E, Petit D, Seguin JR, Boivin M, Tremblay RE and Montplaisir JY. 2007. Associations between sleep duration patterns and behavioral/cognitive functioning at school entry. Sleep 30(9): 1213-1219.

Wachs TD, Uzgiris IC, and Hunt JM. 1971. Cognitive development in infants of different age levels and from different environmental backgrounds: An explanatory investigation. Merrill-Palmer Quarterly 17: 283-317.

Wachs TD. 1976. Utilization of a Piagetian approach in the investigation of early experience effects: a research strategy and some illustrative data. Merrill-Palmer Quarterly 22: 11-30.

Wachs TD and Camli O. 1991. Do ecological or individual characteristics mediate the influence of the physical environment on maternal behavior? Journal of Environmental Psychology 11: 249-264.

Waters E and Valenzuela M. 1999. Explaining disorganized attachment: Clues from research on mildly to moderately undernourished children in Chile. In: J. Solomon and C. George (eds), Attachment disorganization. New York: Guildford Press.

Content last modified 3/14