title: The emergence of probabilistic reasoning in very young infants: evidence from 4.5- and 6-month-olds.
abstract: 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).
authors.affiliation: Department of Psychology, University of California, Berkeley, 3210 Tolman Hall, Berkeley, CA 94720-1650, USA. smdeniso@berkeley.edu
authors.forename: Stephanie
authors.initials: S
authors.lastname: Denison
authors.forename: Christie
authors.initials: C
authors.lastname: Reed
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
mesh_terms: D000704:Analysis of Variance; D001288:Attention; D002657:Child Development; D003210:Concept Formation / Q000502:physiology*; D005260:Female; D005793:Generalization, Psychological / Q000502:physiology*; D006801:Humans; D007223:Infant; D008297:Male; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D011336:Probability; D021641:Recognition, Psychology; D013997:Time Factors