Children undergo dramatic changes in thinking between 2 and 6 years of age. They learn about objects in the world and how they work, and they learn about the natural world – including people, their behaviors and their less obvious traits. All of this information can be systemized in generalizations: categories and concepts. We have studied several kinds of changes in children’s categorization, conceptual knowledge, and reasoning and problem-solving (e.g., tool-use). Expand the topics below or follow the links to learn more about our work on these topics.
Concepts and Category-Based Inferences
We commonly encounter a super-abundance of information. Children must develop thought processes to limit and organize this information. One mechanism is categorization: treating different instances as equivalent (or nearly so). Categorization lets us generalize knowledge from old to new examples: If I believe squirrels love acorns and I see a new squirrel, I will infer that it likes acorns. At what age can children make these ‘leaps of knowledge’ – what philosophers call inductive inferences? We have shown that children as young as 4 years of age can use subtle cues to category membership to infer novel or hidden properties. For example, even though a dolphin looks like a shark, if children know that dolphins are mammals they will infer that dolphins share some ‘deep’ properties with other, very different-looking mammals like dogs or horses. Adults can support children’s inductive inferences by labeling instances (calling a dolphin ‘mammal’), showing children pictures or models that highlight subtle category-specific properties, or teaching category-relevant facts.
Development of Tool-Use
From their first birthday children learn much about objects and materials around them, and how to interact with those things to get things done. We explored how children begin to understand the very concept of function. That is, how do children start to understand that created objects have functions, and the function(s) of an object are abstract properties by which we classify, name, and even sort out objects? We found that between 3 and 4 years children seem to recognize that an object’s typical function is a fundamental property by which we classify and name objects.
Understanding Mental States
When we look at other people we do not perceive a robot carrying out random actions. Every behavior – yawning, absently chewing the end of a pen, furrowing brows in concentration, or laughing happily – brings to mind an underlying mental state: the person is tired, distracted, focused, or amused. We constantly infer other people’s mental states, though we have no direct evidence of these states. Developmental scientists and philosophers have puzzled over a basic question about human thinking: How do children learn to perceive people’s actions as the results of imperceptible mental states? Students and collaborators in the lab have published several studies taht show that even when children seem to have adult-like concepts of mental states, like beliefs or intentions, their concepts are subtly but importantly different than ours.