Infants Parse Dynamic Action

TLDR

Infants observe continuous human motion where pauses are rare and rarely align with intentional action boundaries. The studies aimed to determine whether 10‑ to 11‑month‑old infants can parse ongoing behavior at boundaries linked to the initiation and completion of intentions. After familiarizing infants with digitized continuous everyday actions, the researchers found that infants’ renewed interest was triggered only when motion paused mid‑pursuit of an intention (interrupting test videos). Infants showed heightened interest only when motion was interrupted mid‑intentional action, not when paused at intention boundaries, indicating they detect disruptions in action structure and parse behavior accordingly—a skill that likely underlies later intentional understanding.

Abstract

As observers of human behavior, infants are faced with a complex flow of motion in which pauses are rare and only occasionally coincide with boundaries between intentional actions. Two studies investigated whether, despite such complexity, 10‐ to 11‐month‐old infants ( N = 16 for each study) possess skills for parsing ongoing behavior along boundaries correlated with the initiation and completion of intentions. After being familiarized with digitized sequences of continuous everyday action, infants showed renewed interest in test versions in which motion paused in the midst of an actor's pursuit of intentions (interrupting test videos). In contrast, pauses that suspended motion at intention boundary points (completing test videos) sparked no such renewed interest on infants' part. Moreover, basic salience differences between the two types of test videos were not the source of infants' increased interest when intentions were interrupted (Study 2). These findings demonstrate that infants readily detect disruptions of the structure inherent in intentional action, and hence parse ongoing behavior with respect to such structure. Such parsing skill is likely a prerequisite to the development of genuine intentional understanding.