Developmental change in the use of base-rates and individuating information.

Abstract

Adults tend to make biased inferences when they are given base-rates (i.e., prior probabilities) that conflict with individuating information (i.e., a personality description), relying heavily on individuating information. Recent work has shown that six-year-olds do the same, whereas four-year-olds rely more on prior probabilities. In the present article, we revisit the argument that producing responses that align closely with base-rates should necessarily be seen as normative. We instead posit that rational inferences should be sensitive to all relevant information and should depend on its strength. In three experiments, we explored four-year-olds', six-year-olds' (N = 200), and adults' (N = 196) information use by manipulating the strength of individuating and base-rate information. Across base-rate manipulations, adults showed a bias for individuating information regardless of its strength. In contrast, six-year-olds appeared to use each type of information flexibly, depending on which was more informative. Four-year-olds' performance was less clear: Although they relied on base-rates when they were informative, they struggled to use the individuating information in their inferences and did not appreciate the manipulation of the strength of individuating information. Thus, six-year-olds appear to more flexibly use multiple sources of information than both younger children and adults, suggesting a period in development where children are able to weigh information before they are too biased toward individuating information.

Young children’s use of probabilistic reliability and base-rates in decision-making

“…Base-rate information may be a particularly prominent cue for young children, considering that even infants use probabilistic information to inform their decisions [ 2 , 3 ]. Moreover, recent evidence indicates that base-rate use may be a salient, intuitive response for young children when it is pitted against another piece of information [ 19 , 20 ], consistent also with evidence suggesting that base-rate use is sometimes an intuitive response for adults [ 21 ]. Thus, children might prioritize base-rate information over reliability.…”

“…In light of discovering that 3-year-olds struggle with tracking and choosing between probabilistically reliable machines, we do not test 3-year-olds in subsequent experiments. Instead, we now include 5- and 6-year-old children, which allowed us to explore potential development in children’s use of the information in tandem, given previous work suggesting development in these abilities from 4- to 6-years of age [ 5 , 20 , 25 – 28 ].…”

“…However, prior work also suggests that preschoolers and early school-aged children might consider both pieces of information in their decisions, and there may be developments in this ability throughout early childhood. For example, 4-year-olds consider numerical data in combination with a witness’ testimony [ 25 , 26 ], 5-year-olds update their initial judgements based on numerical information in a task after being given additional evidence about identity [ 5 ], and 6-year-olds flexibly consider base-rates with personality information [ 20 ]. Furthermore, 5-year-old children have an emerging understanding of expected value, which requires integrating the likelihood of obtaining a reward with the value of that reward [ 27 , 28 ].…”