Parental attachment systems: Neural circuits, genes, and experiential contributions to parental engagement

Parental caregiving includes a set of highly conserved set of behaviors and mental states that may reflect both an individual's genetic endowment and the early experience of being cared for as a child. We consider the mental and behavioral elements of early parental caregiving in humans and what is known of the neurobiological substrates of maternal behaviors in mammalian species including some limited human data. Also reviewed briefly is the evidence that specific genes encode proteins that are crucial for the development of the neural substrates that underlie specific features of maternal behavior. Finally, we review the literature on the "programming" role of epigenetic factors in shaping subsequent maternal behavior. Drawing also from recent neuroimaging data, we conclude that there are critical developmental windows during which the genetically determined microcircuitry of key limbic-hypothalamic-midbrain structures are susceptible to early environmental influences and that these influences powerfully shape an individuals responsivity to psychosocial stressors and their resiliency or vulnerability to various forms of human psychopathology later in life.