Generic statements, such as "Bees are striped" are thought to be a central vehicle by which essentialist beliefs are transmitted. But work on generics and essentialism almost never focuses on the type of properties mentioned in generic statements. We test the hypothesis that teleological properties, what something is for, affect categorization judgments more strongly than behavioral, biological, or social properties. In Experiment 1, participants categorized properties as being either behavioral, biological, social, or teleological. In Experiment 2, we used the top four properties from each group to describe a generic noun or a specific individual. Participants then categorized creatures that had one of their properties transformed. We found that changes to teleological properties had the strongest impact on categorization judgments. In Experiment 3, we also found that teleological properties mattered more in an induction task. We suggest that teleological properties play this privileged role in categorization because they are treated as essential properties.