Evaluating Overinclusive Thinking: Development and Validation of the Categorical Overinclusive Thinking Task (COverTT)

Overinclusive thinking, characterized by flexible category boundaries and broad associative networks, is closely linked to creativity. However, there has been a lack of rigorous psychometric evaluation of tasks measuring overinclusive thinking. In this paper, we introduce the Categorical Overinclusive Thinking Task (COverTT) and evaluate its reliability and validity. Across three studies involving 749 participants, we explore the relationship between overinclusive thinking, creativity, openness, creative behaviors, intelligence, and schizotypy. Our findings demonstrate that the COverTT is a reliable tool for assessing overinclusive thinking. Furthermore, we discuss the relationship between the COverTT and the criterion validity measures. To enable other researchers to readily use the COverTT for measuring overinclusive thinking, we provide open access to our data, code, and materials at OSF (https://osf.io/c3phq/?view_only=2973ca020429414db1ea069ede02bed5).