A recent collaborative study between VCU, University of Virginia, and Lund University in Sweden, explores the effects of a child’s environment during their cognitive development.
Dr. Kenneth S. Kendler MD, professor of psychiatry at VCU, worked alongside other researchers and found that statistically, adopted children had a higher IQ than their non-adopted peers.
The reason, according to Kendler, is that the adoptive parents within the study were often of higher socio-economic and educational class, and were often more involved in their child’s cognitive development by doing things such as reading to their child and sharing family meals.
The study worked by comparing 436 sibling relationships. Within each sibship, the children observed were separated into two families, with one sibling raised by their biological parent or parents, while the other was raised by adoptive parents. The siblings were between the ages of 18-20 when their IQ scores were measured, and done so through a two-day process utilized by the Swedish Military to test IQ.
The parents of the children were rated based on their education on a scale from one to five. Within this study, the adoptive parents averaged a higher level of education than that of the biological parents.
The study found that the adopted siblings had an average IQ that was 4.41 points above their siblings who were reared by their biological parents. Also, for every unit of education that the parent had, the child gained around 1.71 IQ points.
In a press release, Kendler asserted that due to the imbalance of children available for adoption and the number of adoptive parents, “adoption agencies see it as their goal of selecting relatively ideal environments within which to place adoptive children.”
A scenario is generated where organizations are given the power to select a near-perfect environment for proper child development. Because there are more parents than there are children, adoption agencies have the ability to reject applicants on minute details which they feel would negatively impact the child’s growth.
Adoption agencies, under state law of all 50 U.S. states, require applicants to submit to a home visit and inspection, which involves communication with all members living within a household. Questions often posed to applicants include their motivation to adopt, expectations for the child’s future, insurance available and educational background of the parents.
Through this questioning, the agencies may determine a parent’s ability to properly care for children. In biological parenting however, children can be raised in a home far from ideal and not be given the same opportunities.
Furthering the point that education and status are the main factors in development, not the actual fact that the child was adopted. It was found that when biological parents had higher education than adoptive ones, the child’s IQ was actually higher.
“We’re not denying that cognitive ability has important genetic components,” Kendler said. “But it is a naïve idea to say that it is only genes. This is strong evidence that educated parents do something with their kid that makes them smarter and this is not a result of genetic factors.”
There is an ongoing debate as to whether prospective parents should face a licensing process similar to those potential adoptive parents face. This is generally thought of as a conservative vs. liberal conflict centered around increased federal power and the protection of children.
Licensing for having children is not currently mandated. However, a Child Care License is required under federal law for any person or organization that wishes to house children, such as a daycare or home care establishment.
“I don’t think that we need ‘testing’ for parents,” Kendler said. “But I believe this is information that could be very helpful for parents.”
A scientific study by Sarah H. Norgate at the University of Salford in 2006, titled “A Critical Analysis of IQ Studies of Adopted Children” does not agree with the statistical data that Kendler’s study puts forth.
While Kendler asserts that the study was not centered around the variable of the child being adopted, rather the education of the parents, Norgate’s study found that adopted children possess a significantly lower IQ than their biological counterparts.