Infants and children face an incredibly complex world, filled with multifaceted objects, people, places and events. When we are faced with all of these complex things, how do we simplify and make sense of our current environment? We must have to classify or generalize a great deal. But how do children learn what to classify or how to generalize? For example, the color of a Lego block might not matter, but it’s shape does. However, color categories often matter for food: green or red apples are both edible (though the ‘green’ category tastes more sour), but a brown or black apple falls into the ‘Do not eat!” category. We have done research on how children make generalizations and form categories based on what features are important.
In earlier studies, we found that the instructions given to 4-year-old children influence how they categorize objects: Asking children “Which things go together” versus “Which ones are the same kind?” will elicit different answers (Deák & Bauer, 1995).
We also found that preschool children were more likely to classify same-category but different-looking things together (think of a dolphin and a dog — both mammals, but very different-looking) under several conditions: First, if the items were fairly detailed, so children could perceive subtle features related to category membership (such as whiskers on dolphins), they were more likely to ignore overall appearances. Second, if adults used a category label (i.e., called the items “mammal”– even if children are not sure what that measures), children would ignore overall appearances. Third, if children were asked to generalize a category-relevant features (e.g., “is warm-blooded”) rather than just put like things together, they were more likely to ignore overall appearances (Deák & Bauer, 1996).
These results and others (e.g., Long et al, 2012) suggest that children take into account a variety of information when deciding the significance of category membership, or inferring how properties generalize to new instances or situations.