Clinical Implications of Attachment
Jay Belsky The Pennsylvania State University
Teresa Nezworski University of California, Santa Barbara
Only a decade ago, students of human development were routinely taught that individual differences in infant functioning in the first year of life were not predictive of later development. Despite this, many continued to pursue the question of the origins of individual differences that emerge after the period of infancy and that are so evident in human functioning across the lifespan. In fact, even in the face of all too consistent evidence indicating that individual differences were not stable from infancy to the childhood years, either in domains of intelligence or social and affective functioning, the collection of data that could radically alter this state of knowledge continued unabated.
In the absence of much evidence that individual differences were stable, clearly articulated positions emerged as to why such continuity should not be expected and could not be found. One point of view with respect to cognitive development was that the transition from sensorimotor intelligence, characteristic of the infant years, to symbolic intelligence, characteristic of the child, adolescent, and adulthood years, was qualitative in nature and, therefore, relatively impervious to stable individual differences ( McCall, 1979). Additional theoretical support for this conclusion came from evolutionary arguments that asserted that development in the opening year or two of life was highly canalized and that unless the individual encountered gross deprivation in his/her rearing environment, normative variation in sensorimotor intelligence would not be predictive of variation in later intelligence ( Scarr- Salapatek, 1976).
In the realm of social and affective development, stable individual differences were also strikingly difficult to document from infancy through