Daphna Buchsbaum | Understanding Abstraction and Conceptual Representation Across Development and Across Species

Institute of Human Development / Developmental Psychology Colloquium

Imagine encountering a novel fruit. Even though you have never seen it before, you will be able to make a number of predictions about it: it may be edible, it may have seeds, and the tree it's growing on probably has more fruits like it. Moreover, other trees like this one probably grow the same fruit as well. The capacity for abstraction allows humans to learn and generalize quickly from sparse data, allowing us to make wide ranging predictions in new situations. Previous research has suggested that humans may be the only species capable of abstract knowledge formation, but this remains controversial, and there is also mixed evidence for when this ability emerges over human development. In the first part of this talk, I will present studies investigating abstract rule formation in capuchin monkeys, chimpanzees, and children in experiments guided by the predictions of a hierarchical Bayesian cognitive model. In the second part of this talk, I will present early work on a combination of computational and empirical methodologies aimed at directly measuring children's categorical organization, and charting the trajectory of categorical development. Our first method is based on machine learning techniques (deep metric learning) that allow us to understand how children implicitly organize their categories, using data from a simple sorting game that is intuitive to children. Our second method (MCMC with children) explores children's categorical representations using adaptively generated rather than hand-picked stimuli, and obtains fine-grained information about the kinds of items that the child considers to be category members. I will present proof-of-concept results for these methods, demonstrating age-dependent differences in how fruit categories are structured, and ongoing work exploring richer category structures such as the development of color concepts and knowledge of biological kinds.