Study Finds Family Environment Critical To Child's IQ

December 20, 2007

Keith Brannon
Phone: (504) 862-8789

The quality of caregiving a child receives within the first two years of life directly affects brain development and IQ, according to a study by a team of researchers from Tulane and other universities.

The study, which followed abandoned young children in Romanian orphanages over time, found that those placed in foster care at younger ages had significantly higher IQ's than those placed in foster care after the age of 2.

"Our findings suggest that there may be a sensitive period in the first two years of life in which experiences are especially important in shaping cognitive development," said principal investigator Charles Zeanah, professor and chief of child psychiatry at Tulane University School of Medicine."This work adds to a growing body of scientific evidence about the importance of early relationship experiences."

The research, which is conducted in collaboration with Charles Nelson at Harvard University, Nathan Fox at the University of Maryland, Peter Marshall at Temple University and

Anna Smyke, also in child psychiatry at Tulane University School of Medicine, appears in the Dec. 21, 2007, issue of the journal Science, published by the AAAS, the science society, the world's largest general scientific organization.

The study tracked 136 children between the ages of six months to 30 months who had been abandoned at birth or soon thereafter and placed into institutions in Bucharest, Romania. Researchers trained social workers and recruited Romanian families to provide foster care for half the children who were randomly selected.

Children placed in foster care within the first 18 months of life had the greatest gains in cognitive development compared to those placed in foster care later. For example, at the age of 42 months, those placed in foster care before 18 months old had an average IQ of 94 compared with scores of 89 for similarly aged children placed in foster care starting between 18 to 24 months. The cognitive gains were less impressive for those placed in foster families between the ages of 24 to 30 months; those children had an average IQ of 80, while children placed with foster families after 30 months had an average IQ of 79.7.

A follow-up survey of the same children a year later showed IQ's for the two groups placed in foster care after two years of age continued to significantly lag behind the group placed with families earlier in life.

The results of the study have implications for countries grappling with how best to care for abandoned, orphaned and abused children and re-enforce policies that favor foster families over institutionalized care for very young children.  Also, the model of foster care implemented in the study may be useful in the United States, where 500,000 children are currently in care.

A copy of the study is available at


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