Parental behaviors do not have a significant influence on a child's later-life intelligence, according to new research.
The research team, led by Kevin Beaver, a criminology professor at Florida State University, publish their findings in the journal Intelligence.
According to Beaver and his team, the link between parenting and offspring intelligence is controversial. Some studies claim that parental behavior toward their children can influence how intelligent they will be in adulthood. But Beaver and other researchers suggest that this association may be incorrect because such studies have not accounted for genetic transmission.
With this in mind, the researchers decided to study the link between parental behavior and later-life intelligence among a nationally representative sample of youths.
For comparison, the team also analyzed aged-match adopted youths who were part of the National Longitudinal Study of Adolescent Health. "The sample of adoptees is able to more fully control for genetic confounding," the researchers note.
At the time of publication, Medical News Today did not have access to the total number of participants included in the study.
The way a child is parented 'will not have a detectable effect on their IQ'
The behaviors of participants' parents were assessed, and participants completed an IQ test that measured verbal intelligence - the Picture Vocabulary Test - while at middle and high school. They completed the IQ test again when they were between the ages of 18 and 26.
The researchers say they found that - among both groups - the influence of parental behavior on child intelligence during adolescence and young adulthood was "marginal and inconsistent."
"Sensitivity analyses that focused only on monozygotic twins also revealed no consistent associations between parenting/family measures and verbal intelligence," they say, adding:
"Taken together, the results of these statistical models indicate that family and parenting characteristics are not significant contributors to variation in IQ scores."
Beaver notes that their findings challenge previous research indicating that parental actions influence a child's intelligence. "In reality," he says, "the parents who are more intelligent are doing these things and it is masking the genetic transformation of intelligence to their children."
He points out, however, that this does not mean parents should not interact with their children. "But the way you parent a child is not going to have a detectable effect on their IQ," he adds, "as long as that parenting is within normal bounds."
Earlier this year, MNT reported on a study claiming that children who have strong reading skills are more likely to have higher intelligence levels in young adulthood.
Another study, published in the journal Psychological Science, suggested that children's drawings at the age of 4 years may be a predictor of their intelligence at the age of 14.
But Dr. Rosalind Arden, leader of the study, said that this does not mean that a child's later-life intelligence is solely dependent on their drawing abilities. "There are countless factors, both genetic and environmental, which affect intelligence in later life," she added.