Dana Johnson, the principal investigator of the study, and his colleagues in the Medical School studied 136 healthy institutionalized infants (average age 21 months) from six orphanages in Bucharest, Romania.
Of these, half were randomly assigned to remain in their facilities and half were assigned to a foster care program.
Their growth rates and measures of intelligence over time were assessed, and they were compared with each other and with a group of 72 never-institutionalized children at 30, 42 and 54 months of age.
Caregiving environments were evaluated by analyzing and coding 90-minute videotapes of the children interacting with their preferred caregivers.
At the beginning of the study, institutionalized children displayed compromised growth and development, with more severe deficits among those who were born weighing less than 5.5 lbs.
Children assigned to foster care showed rapid increases in height and weight (but not head circumference), so that by 12 months, 100 percent of them were in the normal range for height, 90 percent were in the normal range for weight, and 94 percent were in the normal range of weight for height.
Caregiving quality was a predictor of this catch-up growth. Components of the caregiving-quality score positively correlated with catch-up included sensitivity (child-centered, contingent responses) and positive regard for the child (acceptance, respect and warmth, including expressions of physical affection).
Children whose height caught up to normal levels also appeared to improve their cognitive (thinking, learning and memory) abilities. Each incremental increase of one in standardized height scores between baseline and 42 months was associated with an average increase of 12.6 points in verbal IQ.
The study appears in the June print issue of Archives of Paediatrics and Adolescent Medicine, one of the JAMA/Archives journals. (ANI)