The Emergence of Probabilistic Reasoning in Very Young Infants: Evidence from 4.5- and 6-Month-Olds

• Published in: Developmental psychology Vol. 49; no. 2; pp. 243 - 249
• Main Authors: Denison, Stephanie, Reed, Christie, Xu, Fei
• Format: Journal Article
• Language: English
• Published: Washington, DC American Psychological Association 01-02-2013
• Subjects: Analysis of Variance; Attention; Babies; Balls; Bayesian analysis; Bayesian Statistics; Biological and medical sciences; Child Development; Cognition & reasoning; Cognitive ability; Cognitive Development; Computation; Concept Formation - physiology; Developmental psychology; Experiments; Female; Fundamental and applied biological sciences. Psychology; Generalization (Psychology) - physiology; Human; Humans; Infancy; Infant; Infant Development; Infants; Inferences; Learning; Male; Newborn. Infant; Photic Stimulation; Predictive Value of Tests; Probabilistic reasoning; Probability; Probability theory; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Reasoning; Recognition (Psychology); Sampling; San Francisco Bay; Time; Time Factors; Visual Attention; Young Children; Human; Learning; Acquisition process; learning mechanisms; looking time; Infant; Cognition; Cognitive development; Probabilistic reasoning; cognitive development in infancy; Age
• ISSN: 0012-1649; 1939-0599
• DOI: 10.1037/a0028278

How do people make rich inferences from such sparse data? Recent research has explored this inferential ability by investigating probabilistic reasoning in infancy. For example, 8- and 11-month-old infants can make inferences from samples to populations and vice versa (Denison & Xu, 2010a; Xu & Denison, 2009; Xu & Garcia, 2008a). The current experiment investigates the developmental origins of this probabilistic inference mechanism with 4.5- and 6-month-old infants. Infants were shown 2 large boxes, 1 containing a ratio of 4 pink to 1 yellow balls, the other containing the opposite ratio. The experimenter sampled from, for example, the mostly pink box and removed a sample of either 4 pink and 1 yellow balls or 4 yellow and 1 pink balls on alternating trials. Six-month-olds but not 4.5-month-olds looked longer at the 4 yellow and 1 pink sample (the improbable outcome) than at the 4 pink and 1 yellow sample (the probable outcome). (Contains 1 table, 2 figures and 5 footnotes.)