Testimony bias lingers across development under uncertainty.

Children have a powerful ability to track probabilistic information, but there are also situations in which young learners simply follow what another person says or does at the cost of obtaining rewards. This latter phenomenon, sometimes termed bias to trust in testimony, has primarily been studied in children preschool-age and younger, presumably because reasoning capacities improve with age. Less attention has been paid to situations in which testimony bias lingers-one possibility is that children revert to a testimony bias under conditions of uncertainty. Here, participants (4 to 9 years old) searched for rewards and received testimony that varied in reliability. We find support for testimony bias beyond preschool-age, particularly for uncertain testimony. Children were sensitive to trial-by-trial uncertainty (Experiment 1: N = 102, 59 boys, 43 girls; the sample included nine Hispanic/Latinx, 93 non-Hispanic/Latinx participants, of whom six were Black/African American, seven were Asian American, eight were multiracial, 77 were White, and four indicated "other" or did not respond), and with uncertainty defined as a one-time, unexpected change in the testimony (Experiment 3: N = 129; 68 boys, 61 girls; the sample included 12 Hispanic/Latinx, 117 non-Hispanic/Latinx [10 Black/African American, four Asian American, nine multiracial, 103 White, and three "other"]). However, the impact of the testimony bias decreased with age. These effects were specific to the testimony coming from another person as opposed to resulting from a computer glitch (Experiment 2: N = 89, 52 boys, 37 girls; five Hispanic/Latinx, 80 non-Hispanic/Latinx, of whom one was Black/African American, three were Asian American, 15 were multiracial, 66 were White, and four did not report race). Taken together, these experiments provide evidence of a disproportionate influence of testimony, even in children with more advanced reasoning skills. (PsycInfo Database Record (c) 2021 APA, all rights reserved).