Cognition

The reported effects of growth retardation on children's cognition vary with the age at the time of assessment. Deficits are less likely to be detected in infancy after that, most studies through to adolescence have shown a small, statistically significant deficit in IQ; marked mental retardation is not usually seen. Deficits tend to be larger in more severely growth retarded children and are aggravated by high levels of infection, poor nutrition, low levels of stimulation and parental education, as well as other conditions associated with poverty. Poor school achievement has been reported from over half the studies in which it was examined. Data from older adolescents and adults generally come from old studies with large attrition rates, and differences have less often been demonstrated.