Research suggests that respondents vary in their tendency to use the response scale of typical (Likert‐style) questionnaires. We study the nature of the response process by applying a recently introduced item response theory modeling procedure, the three‐process model, to data of self‐ and observer reports of personality traits. The three‐process model captures indifferent, directional, and extreme responding. Substantively, we hypothesize that, and test whether, trait Honesty‐Humility is negatively linked to extreme responding. We applied the three‐process model to personality data of 577 dyads (self‐ and observer reports of the HEXACO Personality Inventory‐Revised; Lee & Ashton, ) of Dutch and German undergraduate respondents. First, we provide evidence that indifferent, directional, and extreme responding can be separated from each other in personality data through the use of the three‐process model. Second, we show that the various response processes show a pattern of correlations across traits and rating sources which is in line with the idea that indifferent and extreme responding are person‐specific tendencies, whereas directional responding is content‐specific. Third, we report findings supporting the hypothesis that Honesty‐Humility is negatively linked to extreme responding. In Likert‐based personality data, applying the three‐process model can unveil individual differences in the response process.