Bounded rationality and human development

Although multi-scale, multi-directional feedback between genes, brain, cognition, and behaviour is the cornerstone of well-evidenced interactionist models of human development (e.g., Gottlieb, 2007), contemporary theories of neurodevelopmental variation and disorder characteristically describe only unidirectional cascades across this hierarchy. To complement this dominant view, I present a new theoretical account of the cognitive and behavioural origins of individual differences in human development. This account is grounded in the ideas of restricted search and satisficing that are central to the bounded rationality paradigm (Simon, 1955, 1956, 1990), and which set this account apart from claims that agents optimise utility functions or maximise their learning. I develop a new formal model of adaptive restricted search and satisficing that incorporates reciprocal influences on development and learning, and integrate a broad contemporary empirical literature in support of this model. This work motivates the novel position that adaptive restricted search and satisficing not only amplify neurodevelopmental differences beyond their primary neurogenetic origins (explaining developmental multifinality and fanning) but also provide a route by which disparate primary causal processes are anchored to common phenotypes (explaining developmental equifinality). While the focus of this paper is on early developmental variation and conditions of clinical significance, I argue that bounded rationality offers a general paradigm through which to understand the emergence of individual differences across the lifespan, from psychopathology to expertise. The recommendation of this report is that cognitive and behavioural feedback should be embedded more widely into causal process models of the origins of individual differences in human development.