No abstract

Cognitive development is marked by age-related improvements across a number of domains, as young children perform worse than their older counterparts on most tasks. However, there are cases in which young children, and even infants, outperform older children and adults. So when, and why, does being young sometimes confer an advantage? This article provides a comprehensive examination of the peculiar cases in which younger children perform better. First, we outline the specific instances in which younger is better across domains, including mastering language, using probabilistic information, detecting causal relations, remembering certain information, and even solving problems. We then examine how children’s reduced cognitive abilities, ongoing brain development, more limited prior knowledge, and heightened tendency to explore benefits their learning, reasoning, perception, and memory from a mechanistic perspective. We hold that considering all of these factors together is essential for understanding the ways in which children’s learning is unique and that science has much to learn from a careful consideration of childhood.

Classic literature in judgment and decision-making shows that when testimony information conflicts with base-rates, adults typically underuse base-rate information and rely heavily on testimony (Bar-Hillel, 1980; Lyon & Slovic, 1976; Tversky & Kahneman, 1981). Although children can use base-rates (Denison, Konopczynski, Garcia, & Xu, 2006; Kushnir, Xu, & Wellman, 2010) and testimony (Koenig & Harris, 2005) separately in their inferences, whether they show a similar tendency toward weighing testimony more heavily is unknown. Four- and 5-year-old children were asked to guess the color of a dog’s collar, drawn from a group of 10 dogs (e.g., 8 blue: 2 yellow). Children were also presented with testimony about the dog’s collar that was from either a previously accurate or inaccurate witness. In Experiment 1 (N = 120), children were presented with only base-rate or testimony information. They relied on base-rates at above chance levels and relied on testimony at rates that approximately matched the witness’s previous accuracy. In Experiment 2 (N = 160), when base-rates and testimony were presented together and conflicted, a majority of children endorsed the color consistent with the accurate witness’s testimony, neglecting base-rates. However, when presented with the inaccurate witness’s testimony, children were more likely to endorse the color indicated by the base-rates. Children appear to rely on the testimony of an accurate but fallible witness, revealing that a tendency to neglect base-rates in favor of testimony emerges early in development, yet they remain sensitive to the witness’s accuracy when presented with multiple sources of information.

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.

Children are skilled reasoners who readily use causal, reliability, and base-rate (i.e., prior probability) information in their decisions. Though these abilities are typically studied in isolation, children often must consider multiple pieces of information to make an informed decision. Four experiments (N = 320) explored the development of children’s ability to use reliability and base-rate information when making decisions about draw outcomes. Experiment 1 examined the age at which children can first compare and choose between probabilistically reliable machines. Three- and 4-year-old children saw machines that were probabilistically reliable at obtaining objects while sampling from uniform distributions (i.e., all target or non-target objects). Although 4-year-old children correctly used reliability in their decisions, 3-year-olds did not. In Experiment 2a, 4- to 6-year-olds were presented with the same probabilistically reliable machines, although they sampled from a mixture of target and non-target items. Here, children tended to choose the machine with the better proportion of targets, regardless of reliability. This was replicated in Experiment 2b. In Experiment 3, children were presented with one perfectly reliable machine and one probabilistically unreliable machine. Here, children continued to mostly choose the machine with the better proportion of targets. These results raise questions about base-rate overuse early in development and highlight the need for additional work on children’s ability to use multiple pieces of information in decision-making.