The case for child development as a determinant of health.

The complex relationship between life course and social/economic-psychosocial conditions in a given society has a powerful determining effect on human health. The socioeconomic gradient emerges from a complex mixture of psychosocial and material influences operating at various levels of social aggregation and, also, a series of biological responses whose character and significance vary over the life course. Biological embedding and the "latency" and "pathways" model incorporate the notion of a critical period in development; the pathways model emphasizes the cumulative effect of life events and the ongoing importance of social/economic-psychosocial conditions throughout the life cycle. The models, although conceptually complementary, result in ideological conflict and lend themselves to different policy directions.