Socio-environmental conditions can also regulate the molecular composition of CNS cells, and thereby alter psychological and behavioral responses to future environments (Zhang et al., 2006). Because the molecular composition of our cells constitutes the physical machinery by which we perceive and respond to the world around us (“Body” in Figure 3), and that molecular composition is itself subject to remodeling by socoio-environmental influences, gene expression constitutes both a cause and a consequence of behavior. RNA can be construed as the physical medium of a recursive developmental system in which social, behavioral, and health outcomes at one point in time also constitute inputs that shape our future responses to the environment (e.g., as in Heckman’s model of human capability development, which analyzes how capacities developed at Time1 impact our ability to capitalize on environmental opportunities at Time2 (Heckman, 2007)). Future research will push these models out of accessible immune cells and into the more sensitive CNS structures that shape social, cognitive, and affective processes. It will also be critical to define the particular features of social environments that trigger transcriptional remodeling
