Evaluating overinclusive thinking: Development and validation of the Categorical Overinclusive Thinking Task (COverTT)

Overinclusive thinking, characterized by flexible category boundaries and broad associative networks, has been linked to creativity. However, overinclusive thinking has lacked rigorous psychometric evaluation grounded in the cognitive psychology of categorization. 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 find small but reliable correlations between the COverTT and openness/creative behaviors. 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/).