Categories and Constraints in Causal Perception

• Published in: Psychological science Vol. 28; no. 11; pp. 1649 - 1662
• Main Authors: Kominsky, Jonathan F., Strickland, Brent, Wertz, Annie E., Elsner, Claudia, Wynn, Karen, Keil, Frank C.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Sage Publications, Inc 01.11.2017; SAGE Publications; SAGE PUBLICATIONS, INC; Association for Psychological Science
• Subjects: Adult; Causality; Child Development - physiology; Cognitive Sciences; Humans; Infant; Infants; Life Sciences; Motion Perception - physiology; Neurons and Cognition; Perceptions; Perceptual speed; Psychomotor Performance - physiology; Research Article; Task performance; Thinking - physiology; open materials; open data; naive physics; causality; perception; infant development
• ISSN: 0956-7976; 1467-9280; 1467-9280
• DOI: 10.1177/0956797617719930

When object A moves adjacent to a stationary object, B, and in that instant A stops moving and B starts moving, people irresistibly see this as an event in which A causes B to move. Real-world causal collisions are subject to Newtonian constraints on the relative speed of B following the collision, but here we show that perceptual constraints on the relative speed of B (which align imprecisely with Newtonian principles) define two categories of causal events in perception. Using performance-based tasks, we show that triggering events, in which B moves noticeably faster than A, are treated as being categorically different from launching events, in which B does not move noticeably faster than A, and that these categories are unique to causal events (Experiments 1 and 2). Furthermore, we show that 7- to 9-month-old infants are sensitive to this distinction, which suggests that this boundary may be an early-developing component of causal perception (Experiment 3).