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

Study shows how bias can influence people estimating the ages of other people

October 17, 2018
A trio of researchers from the University of New South Wales and Western Sydney University has discovered some of the factors involved when people make errors in estimating the ages of other people. In their paper published ...

Infants are more likely to learn when with a peer

October 16, 2018
Infants are more likely to learn from on-screen instruction when paired with another infant as opposed to viewing the lesson alone, according to a new study.

Researchers use brain cells in a dish to study genetic origins of schizophrenia

October 16, 2018
A study in Biological Psychiatry has established a new analytical method for investigating the complex genetic origins of mental illnesses using brain cells that are grown in a dish from human embryonic stem cells. Researchers ...

Income and wealth affect the mental health of Australians, study shows

October 16, 2018
Australians who have higher incomes and greater wealth are more likely to experience better mental health throughout their lives, new research led by the Bankwest Curtin Economics Centre has found.

Linguistic red flags from Facebook posts can predict future depression diagnoses

October 15, 2018
In any given year, depression affects more than 6 percent of the adult population in the United States—some 16 million people—but fewer than half receive the treatment they need. What if an algorithm could scan social ...

Early changes to synapse gene regulation may cause Alzheimer's disease

October 15, 2018
Alzheimer's disease (AD) is the most common form of dementia, involving memory loss and a reduction in cognitive abilities. Patients with AD develop multiple abnormal protein structures in their brains that are thought to ...

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.