Parents of youth and young adults with intellectual and developmental disabilities: Barriers experienced during transition.

Collective behavior is crucial for animal survival, and can emerge from simple local interactions among individuals. Understanding the exact nature of these local interactions, or the behavioral “rules” that animals use to respond to their group mates has been the focus of extensive experimental and theoretical studies. Importantly, moving animal groups, such as schooling fish or flocking birds, can exhibit a diversity of stable collective states, such as schooling (directed group motion), swarming (disordered motion), and milling (circular motion around a center point), and the ability to dynamically switch between states. Theoretical and experimental studies indicate that such diversity of collective states can emerge from static local interactions among individuals. Specifically, simulated groups of moving agents exhibit different emergent collective states depending on the initial and boundary conditions of the system. Experimental evidence in schooling fish supports these theoretical findings, indicating that groups can transition between multiple stable behavioral regimes, or states, while implementing static interactions among individuals. However, assuming inter-individual interaction rules to be static and hardwired ignores the fact that all living systems require plasticity and feedback regulation to maintain homeostasis. In particular, social interactions need to be flexible to allow individuals in groups to respond to evolving social and environmental demands. Indeed, experimental studies indicate that shoaling and schooling behaviors in fish, as well as collective motion in locusts, depend on previous experience with conspecifics and early-life social exposure, suggesting that these behaviors have a learned component. Yet, little is known about the mechanisms that allow animals to adaptively modulate their inter-individual interactions and the resulting collective behaviors, based on previous experiences, internal states, and behavioral goals.