Résumé : The GEOCAT is a short nonverbal test for measuring two types of cognition that tally with Freud’s distinction between primary and secondary unconscious processes: attributional and relational similarity judgment. Attributional similarity judgment is a mode of cognitive categorization in which stimuli are classified based on perceptual resemblances between attributes and features, just like in primary processing. Relational similarity judgment is a mode of cognitive categorization that builds on higher order relationships between stimuli, just like in secondary processing. The GEOCAT can be used in diverse research contexts, and test administration takes 2 minutes. The present study investigates the construct validity and internal consistency of this instrument in a sample of Belgian university students. A confirmatory factor analysis for binary items indicates that a dimension reflecting relational or attributional categorization processes lies behind the GEOCAT items, that this model has a good fit to the data, and that all items are equally good indicators of these processes. We also compared the GEOCAT to an alternative measure that builds on a continuous scale for similarity judgment. Correlations between corresponding subscales were moderate and three GEOCAT items proved to be problematic. Internal consistency proved to be good. Suggestions for future research on similarity judgment and primary and secondary processes are discussed.