By Annie Stuart
WebMD Feature Reviewed by Brunilda Nazario, MD

Aside from genetics, what influences your child's IQ? Clearly, good nutrition, protection from toxins, and plenty of playtime and exercise can nurture a child's intelligence. But can you really boost your child's IQ?

Many child development experts now focus less on measuring a child's IQ than on helping children reach their full intellectual potential - and without adding too much pressure.

WebMD talked with the experts about how a child's intelligence develops. None of them is touting the flashiest toys, computer programs, or latest Baby Mozart video - and you may find that their insights help your child's IQ far more than any fad.

A Child's IQ: How does a child's brain develop?

From before birth to age 4, an infant's brain grows explosively. In fact, your child's brain has reached 90% of its adult size before kindergarten. This period of great growth provides an ideal window of opportunity for learning.

But the brain doesn't stop developing at age 4. It continues to organize and restructure throughout childhood - even into early adult life - as it becomes more complex. Unfortunately, knowing about the brain's early growth has prompted many parents to panic about their child's IQ or push their kids into "primo preschools."

"It's a classic American concern - how to accelerate learning," says Ross A. Thompson, PhD, professor of psychology at the University of California, Davis. "Many parents believe that if their children learn fast early, they will remain accelerated. But children learn best at a natural rate. Those who show early advances settle out by the time they reach grade school. Others catch up."

The early years do matter, says Thompson. "But lower circuits in the brain must be built before higher circuits, and advanced skills must be based on basic skills," he says.

Your Child's IQ: Emotion drives learning

One of these basic skills involves creating a template for close relationships - usually through early attachment to parents and caregivers. Critical to your child's emotional and social development, attachment also helps build your child's intelligence.

Being attuned to your child's inner mental life helps your child's developing brain become integrated, according to Daniel J. Siegel, MD, director of the Center for Human Development at the UCLA School of Medicine. Writing in Infant Mental Health Journal, Siegel, who studies how relationships affect learning, says being attuned also provides a "safety net" for your child's brain.

"Close, affectionate relationships throughout childhood are important, but especially when a child is little," says Pat Wolfe, EdD. Wolfe is an educational consultant and co-author of Building the Reading Brain, PreK-3. One way to attune to your child is to listen closely and make eye contact. "If you only pretend to listen because you're distracted, kids pick up on that really fast," Wolfe says. Other ways to connect? With your facial expressions, tone of voice, gestures, and other nonverbal signals. Wolfe tells WebMD that when your child is older, one of the best things you can do is to talk about the day.