title: Intuitions of probabilities shape expectations about the future at 12 months and beyond.
abstract: Rational agents should integrate probabilities in their predictions about uncertain future events. However, whether humans can do this, and if so, how this ability originates, are controversial issues. Here, we show that 12-month-olds have rational expectations about the future based on estimations of event possibilities, without the need of sampling past experiences. We also show that such natural expectations influence preschoolers' reaction times, while frequencies modify motor responses, but not overt judgments, only after 4 years of age. Our results suggest that at the onset of human decision processes the mind contains an intuition of elementary probability that cannot be reduced to the encountered frequency of events or elementary heuristics.
authors.affiliation: Language, Cognition, and Development Laboratory, Scuola Internazionale Superiore di Studi Avanzati, International School for Advanced Studies, 34014 Trieste, Italy.
authors.forename: Erno
authors.initials: E
authors.lastname: Téglás
authors.forename: Vittorio
authors.initials: V
authors.lastname: Girotto
authors.forename: Michel
authors.initials: M
authors.lastname: Gonzalez
authors.forename: Luca L
authors.initials: LL
authors.lastname: Bonatti
mesh_terms: D000367:Age Factors; D002675:Child, Preschool; D003071:Cognition; D003657:Decision Making / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular; D005544:Forecasting; D006801:Humans; D007223:Infant; D019545:Intuition / Q000502:physiology*; D007600:Judgment / Q000502:physiology*; D008297:Male; D011336:Probability; D011340:Problem Solving / Q000502:physiology*; D002666:Psychology, Child; D011597:Psychomotor Performance; D011930:Reaction Time; D016037:Single-Blind Method