For the abstracts below, however, you can get the whole article with just one more click. The Groundwork of Cognition.
Categorization is a very basic cognitive activity.
Explanations of categorization range from nativist theories denying that any nontrivial categories are acquired by learning to inductivist theories claiming that most categories are learned. Indeed, the effect of the category boundary is not merely quantitative, but qualitative. The induction and representation of categories. The Groundwork of Cognition. In acquiring a category we learn to label or identify positive and negative instances from a sample of confusable alternatives.