Inherited IQ can increase in early childhood

January 18, 2018 by Ken Branson, Rutgers University
Inherited IQ can increase in early childhood
The best time to boost a child's intelligence is in early elementary school, according to a new Rutgers study. Credit: Rutgers University

When it comes to intelligence, environment and education matter – more than we think.

Those are the findings of Rutgers University psychologists Louis Matzel and Bruno Sauce, based on an integrative review of recent studies on the nature of . Their study is published in the December issue of the Psychological Bulletin, a journal of the American Psychological Association.

 "Genetic influences don't run the show, nor do environmental effects. It's the genetic-environmental interplay that is the ringmaster," said Matzel, a professor of psychology in the School of Arts and Sciences at Rutgers-New Brunswick. Sauce is a graduate student in Rutgers' School of Graduate Studies.

The study, the researchers say, has significant implications for the way we educate children, whose inherited IQ can increase, especially during early childhood, with the right kind of stimulation and attention.  

"We educate children the hard way in this country," Matzel said. "We go to impoverished high schools and try to remediate kids, which is a perfectly good thing to do. But it's often too late; the time to reach those kids is when they start school, while their intelligence is most malleable."

Scientists measure the heritability of traits on a scale of 0.0 to 1.0. Eye color has a heritability score of .99, meaning that it's highly genetic. Intelligence typically rates at .8, Matzel and Sauce said, which means that it, too, is very heritable.  However, Matzel and Sauce believe people often underestimate the role of
"Through interactions and correlations with the environment, genetic influences can be expressed in wildly different ways, and environmental influences are much more powerful than many scientists believe," Sauce said.

The researchers said the heritability of IQ can be as low as .3 in young children, which leaves plenty of room for changes in intelligence. But school systems often ignore this opportunity, they believe, focusing on increasing rote knowledge at the expense of critical thinking. Intervention programs then often fail to create lasting changes to children's environment.

Consider children who take part in Head Start, the federal program that provides low-income children with comprehensive education, nutrition and parent-involvement services. Matzel said those 's IQ scores increase significantly while they're part of the program, but frequently regress after they leave it – a common criticism of these programs. That, he said, is because the stimulation and encouragement received in Head Start is missing when the child returns to their more restrictive environment.

Or consider identical twins separated at birth. If their IQs are nearly identical, and they have equal opportunities, they will be equally smart as adults.  However, if one is deprived of opportunities, their cognitive abilities will diverge, Matzel said.  This highlights the important role that environmental opportunity plays in the establishment of an individual's .

While twins may have the same basic mental equipment with which to face the world, the twin raised in the better environment can thrive while his sibling is thwarted.  "The environment is the critical tool that allows our genetic equipment to prosper," Matzel said.

Explore further: Why is educational achievement heritable?

Related Stories

Why is educational achievement heritable?

October 6, 2014
New research, led by King's College London finds that the high heritability of exam grades reflects many genetically influenced traits such as personality, behaviour problems, and self-efficacy and not just intelligence.

Well-established views on heritable intelligence brought down: Genes and environment play dynamic role together

October 24, 2013
The well-established view that intelligence is largely genetically fixed and hardly malleable has been discarded. A team of Dutch research methodologists at VU University Amsterdam, the University of Amsterdam and Tilburg ...

Genes are not destiny: Environment and education still matter when it comes to intelligence

August 22, 2016
Recent research has suggested that academic performance, reading ability and IQ have a genetic basis. This reinforces the popular notion that intelligence and related cognitive capacities are somehow "in our genes".

Children's drawings indicate later intelligence, study reports

August 18, 2014
How 4-year old children draw pictures of a child is an indicator of intelligence at age 14, according to a study by King's College London, published today in Psychological Science.

Beneficial effects of interventions to raise intelligence in young children fade over time

December 3, 2015
The winner of a decades-old debate about what scientists call the fadeout effect—one of the most persistent research mysteries in intelligence and psychological development—may finally have been decided.

Recommended for you

People are more honest when using a foreign tongue, research finds

August 17, 2018
New UChicago-led research suggests that someone who speaks in a foreign language is probably more credible than the average native speaker.

FDA approves brain stimulation device for OCD

August 17, 2018
(HealthDay)—A brain stimulation device to treat obsessive-compulsive disorder (OCD) has received approval for marketing Friday by the U.S. Food and Drug Administration.

16 going on 66: Will you be the same person 50 years from now?

August 17, 2018
How much do you change between high school and retirement? The answer depends on whether you're comparing yourself to others or to your younger self.

Research eyes role of stress in mental illnesses

August 17, 2018
We all face stress in our lives. Even researchers seeking to understand why some people shrug it off while others face battles against disorders like depression or PTSD.

It's okay when you're not okay: Study re-evaluates resilience in adults

August 16, 2018
Adversity is part of life: Loved ones die. Soldiers deploy to war. Patients receive terminal diagnoses.

Men and women show surprising differences in seeing motion

August 16, 2018
Researchers reporting in the journal Current Biology on August 16 have found an unexpected difference between men and women. On average, their studies show, men pick up on visual motion significantly faster than women do.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

RobertKarlStonjek
not rated yet Jan 20, 2018
The interaction between genes and environment...intelligent unaffiliated people have been saying that all along but those affiliated with one discipline or other tend to side with their biological, social or other one sided agenda...it was never 'Nature verses Nurture', it was 'Social Psychology verses Biology' (just one of many possible examples) and other petty squabbles and childish attempts to annex some intellectual territory or other in the name of their own discipline.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.