Development of Impulse Control, Inhibition, and Self-Regulatory Behaviors in Normative Populations across the Lifespan

Impulsivity represents a complex multidimensional construct that may change across the lifespan and is associated with numerous neuropsychiatric disorders including substance use disorders, conduct disorder/antisocial personality disorder, and traumatic brain injury. Multiple psychological theories have considered impulsivity and the development of impulse control, inhibition, and self-regulatory behaviors during childhood. Some psychoanalytic theorists have viewed impulse control and self-regulatory behaviors as developing ego functions emerging in the context of id-based impulses and inhibitory pressures from the superego. Object relationists added to this framework but placed more emphasis on mother-child dyadic relationships and the process of separation and individuation within the infant. Cognitive and developmental theorists have viewed impulse control and selfregulation as a series of additive cognitive functions emerging at different temporal points during childhood and with an emphasis on attentional systems and the ability to inhibit a prepotent response. Commonalities exist across all of these developmental theories, and they all are consistent with the idea that the development of impulse control appears cumulative and emergent in early life, with the age range of 24-36 months being a formative period. Impulsivity is part of normal development in the healthy child, and emerging empirical data on normative populations (as measured by neuropsychological testing batteries, self-report measures, and behavioral observation) suggest that impulse control, self-regulation, and other impulsivity-related phenomena may follow different temporal trajectories, with impulsivity decreasing linearly over time and sensation seeking and reward responsiveness following an inverted U-shaped trajectory across the lifespan. These different trajectories coincide with developmental brain changes, including early maturation of subcortical regions in relation to the later maturation of the frontal lobes, and may underlie the frequent risk-taking behavior often observed during adolescence.