Normativity in Conceptual Representations

Most previous research on categories and concepts has focused on how people use categories to make descriptive judgments (e.g., to infer whether a particular newly-encountered bird will fly). I found, however, that people also think of many categories prescriptively (e.g., they think that birds are supposed to fly), and these prescriptive beliefs are particularly influential in shaping young children’s concepts. For example, if a person wanted to learn about cheetahs, would it be better to examine a cheetah that runs the average speed for a cheetah, or the one that runs the fastest? This question is important because beliefs about which members of categories are most representative and informative shape how people use categories to learn about the world. In this line of work, I address how prescriptive norms—what people think category members should be like—shape category structure in early childhood. For example, in work with my graduate advisor Dr. Marjorie Rhodes, we found that while adults often think about animal kinds in terms of category averages (e.g., they prefer to learn from the average-speeded cheetah, to account for the fact that cheetahs vary in running speed), young children tend to focus instead on category norms (e.g., they prefer to learn from the very fastest cheetah, since cheetahs should run fast; Foster-Hanson & Rhodes, 2019a). 

These patterns of developmental change are not just a feature of conceptual structure, they also have important implications for learning. For example, we characterized how strategies for learning about animal kinds from samples of evidence change across development. In our work, adults and children aged 9-10 preferred to learn from diverse samples that accounted for the variability within natural kind categories (e.g., the fastest and slowest cheetahs), whereas younger children chose to learn from highly idealized samples (e.g., the two fastest cheetahs; Foster-Hanson, Moty, Cardarelli, Ocampo, & Rhodes, 2020). We're currently investigating whether these same features of category representation could also shape how broadly children generalize new information.

As further evidence of heightened normativity in young children’s concepts, we found that children are more negative in their judgments of animal and social category members that do not conform to their groups (Foster-Hanson, Roberts, Gelman, & Rhodes, under review). Category norms also shape children’s and adults’ inductive reasoning about social role categories (e.g., “scientist”), but young children think more in terms of what people are supposed to do than adults (e.g., they think that scientists are curious because they should be; Foster-Hanson & Rhodes, 2019b). To explore the domain-generality of early normativity in conceptual representations, we're currently exploring whether young children’s representations of gender categories are also characterized by a heightened focus on category ideals.

Young children’s focus on norms about animal categories can lead to long-term difficulties in thinking and reasoning about the natural world and their ability to understand complex scientific concepts, like the scientific method or evolution through natural selection. For these reasons, in another ongoing project in this line of work, Dr. Rhodes and I are developing an intervention strategy to help young children focus more on category variability and less on category ideals when reasoning about the biological world. The ultimate goal of this work is to improve informal science education through a museum exhibit at the American Museum of Natural History, to help foster a greater understanding of category variability throughout development. This is one way in which I use my research to directly benefit diverse populations across the general public.