On the causes of early life experience effects: evaluating the role of mom.

Early life experiences are thought to have long-lasting effects on cognitive, emotional, and social function during adulthood. Changes in neuroendocrine function, particularly the hypothalamic-pituitary-adrenal (HPA) axis, contribute to these systems-level behavioral effects. In searching for causal mechanisms underlying these early experience effects, pioneering research has demonstrated an important role for maternal care in offspring development, and this has led to two persistent ideas that permeate current research and thinking: first, environmental impact on the developing infant is mediated through maternal care behavior; second, the more care that a mother provides, the better off her offspring. While a good beginning, the reality is likely more complex. In this review, we critically examine these ideas and propose a computationally-motivated theoretical framework, and within this framework, we consider evidence supporting a hypothesis of maternal modulation. These findings may inform policy decisions in the context of child health and development.