The long-term effects of early experience.

Empirical research findings are reviewed with respect to the long-term effects of early experiences on intellectual and social development. Particular attention is focused on the question of whether adverse experiences in infancy can lead to enduring impairment, even when later experiences are positive and beneficial. It is concluded that, although there are continuities between infancy and maturity, the residual effects of early experiences on adult behaviour tend to be quite slight, both because of the maturational changes that take place during middle and later childhood and because of the effects of beneficial and adverse experiences during all the years after infancy. The long-term effects of early deprivation depend heavily on whether or not the deprivation continues, but there is a suggestion that, in some circumstances, infantile experiences may have some persisting effects in spite of later environmental change. However, there is a lack of critical data to test this hypothesis.