title: Probability versus representativeness in infancy: can infants use naïve physics to adjust population base rates in probabilistic inference?
abstract: A rich tradition in developmental psychology explores physical reasoning in infancy. However, no research to date has investigated whether infants can reason about physical objects that behave probabilistically, rather than deterministically. Physical events are often quite variable, in that similar-looking objects can be placed in similar contexts with different outcomes. Can infants rapidly acquire probabilistic physical knowledge, such as some leaves fall and some glasses break by simply observing the statistical regularity with which objects behave and apply that knowledge in subsequent reasoning? We taught 11-month-old infants physical constraints on objects and asked them to reason about the probability of different outcomes when objects were drawn from a large distribution. Infants could have reasoned either by using the perceptual similarity between the samples and larger distributions or by applying physical rules to adjust base rates and estimate the probabilities. Infants learned the physical constraints quickly and used them to estimate probabilities, rather than relying on similarity, a version of the representativeness heuristic. These results indicate that infants can rapidly and flexibly acquire physical knowledge about objects following very brief exposure and apply it in subsequent reasoning.
authors.affiliation: Department of Psychology, University of Waterloo.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Denison
authors.affiliation: Department of Psychology, University of California, Berkeley.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Trikutam
authors.affiliation: Department of Psychology, University of California, Berkeley.
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
mesh_terms: D002657:Child Development; D003210:Concept Formation; D053483:Eye Movement Measurements; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011336:Probability; D011581:Psychological Tests; D065855:Spatial Processing; D013850:Thinking; D014796:Visual Perception