Kids Who Get Spanked May Have Lower IQs
Studies Show Link Between Getting Spanked and Poorer Scores on Intelligence Tests
Critics Say Evidence Is Weak continued...
But earlier this month, Duke University research scientist Lisa J. Berlin,
PhD, and colleagues also linked early spanking to reduced intelligence in one
of the most rigorously designed studies to ever address the issue.
The researchers questioned 2,500 racially diverse, low-income moms about
their use of spanking as a discipline tool for their toddlers.
They found that children who were spanked at age 1 were more aggressive than
those who weren't by age 2 and they scored lower on tests to assess mental
development at age 3.
"The research as a whole really paints a picture of the detrimental
long-term effects of physical punishment," Berlin tells WebMD. "The message to
parents is find other ways to discipline your children."
A 2002 analysis of 88 spanking studies spanning six decades linked spanking
to 10 negative behaviors including aggression, anti-social behavior, and mental
More than 90% of the studies found spanking to be detrimental, says
developmental psychologist Elizabeth Gershoff, PhD, who conducted the
"Parents spank to decrease bad behavior in the short and long term and to
promote positive behavior," she tells WebMD. "What the research tells us is
that spanking doesn't seem to be doing either of these things."
But critics say that research is highly suspect because it has largely been
conducted by investigators like Straus, Berlin, and Gershoff who strongly
oppose the practice.
In addition, the studies are often criticized for lacking scientific rigor
-- a charge Gershoff acknowledges is hard to counter.
"We can't very well do experiments in which we tell some parents to spank
their children and others not too," she says.
Straus likens the criticism to that leveled at the early studies linking
smoking to lung cancer.
"For years the tobacco industry was able to destroy the studies one by one
because they all had problems," he says. "No single study was truly definitive.
But in the end the Surgeon General concluded that the evidence as a whole just
couldn't be denied."