“…First, in classic child probability learning studies (Stevenson, 1970), participants made a series of choices between an option reinforced with some probability (100%, 66%, or 33%) and nonreinforced alternatives. Unsurprisingly, child and adult participants selected the reinforced option more often than they did the alternatives (Brackbill, Kappy, & Starr, 1962;Olson, Bibelheimer, & Stevenson, 1967); however, a Ushaped pattern of development emerged, with preschoolers and college students selecting the reinforced option more often than school-aged children, who chose the reinforced option approximately as frequently as it was reinforced (Gruen & Weir, 1964;Stevenson & Zigler, 1958). Second, the Iowa Gambling Task, which recently has been given to children and adolescents, measures how quickly participants gravitate toward safer options while making a series of choices between them and riskier alternatives (Bechara, Damasio, Damasio, & Anderson, 1994;Bechara, Damasio, Tranel, & Damasio, 2005).…”