Developmental Changes in Strategies for Gathering Evidence About Biological Kinds

How do people gather samples of evidence to learn about the world? Adults often prefer to sample evidence from diverse sources—for example, choosing to test a robin and a turkey to find out if something is true of birds in general. Children below age 9, however, often do not consider sample diversity, instead treating non-diverse samples (e.g., two robins) and diverse samples as equivalently informative. The current study (N = 247) found that this discontinuity stems from developmental changes in standards for evaluating evidence—younger children chose to learn from samples that best approximate idealized views of what category members are supposed to be like (e.g., the fastest cheetahs), with a gradual shift across age toward samples that cover more within-category variation (e.g., cheetahs of varying speeds). These findings have implications for the relation between conceptual structure and inductive reasoning, and for the mechanisms underlying inductive reasoning more generally.     

The effect of group status on children's hierarchy-reinforcing beliefs

Members of advantaged groups are more likely than members of disadvantaged groups to think, feel, and behave in ways that reinforce their group's position within the hierarchy. This study examined how children's status within a group-based hierarchy shapes their beliefs about the hierarchy and the groups that comprise it in ways that reinforce the hierarchy. To do this, we randomly assigned children (4–8 years; N = 123; 75 female, 48 male; 21 Asian, 9 Black, 21 Latino/a, 1 Middle-Eastern/North-African, 14 multiracial, 41 White, 16 not-specified) to novel groups that differed in social status (advantaged, disadvantaged, neutral third-party) and assessed their beliefs about the hierarchy. Across five separate assessments, advantaged-group children were more likely to judge the hierarchy to be fair, generalizable, and wrong to challenge and were more likely to hold biased intergroup attitudes and exclude disadvantaged group members. In addition, with age, children in both the advantaged- and disadvantaged-groups became more likely to see membership in their own group as inherited, while at the same time expecting group-relevant behaviors to be determined more by the environment. With age, children also judged the hierarchy to be more unfair and expected the hierarchy to generalize across contexts. These findings provide novel insights into how children's position within hierarchies can contribute to the formation of hierarchy-reinforcing beliefs.

Research Highlights

• A total of 123 4–8-year-olds were assigned to advantaged, disadvantaged, and third-party groups within a hierarchy and were assessed on seven hierarchy-reinforcing beliefs about the hierarchy.
• Advantaged children were more likely to say the hierarchy was fair, generalizable, and wrong to challenge and to hold intergroup biases favoring advantaged group members.
• With age, advantaged- and disadvantaged-group children held more essentialist beliefs about membership in their own group, but not the behaviors associated with their group.
• Results suggest that advantaged group status can shape how children perceive and respond to the hierarchies they are embedded within.