Paul Lodder has been honored with the 2020 Elsevier & EAPM Young Investigators Award. Congratulations!
Type D personality, a combination of the two personality traits negative affectivity (NA) and social inhibition (SI), has been associated with various medical and psychosocial outcomes. Type D effects can be analyzed according to several methods. In this study, a computer simulation revealed that classifying people in personality groups produced false positive Type D effects when only one of the underlying personality traits (NA or SI) was related to an outcome. This problem did not occur when modeling Type D using the continuous NA and SI scores. Reanalysis of two published studies showed that significant Type D effects based on personality groups were no longer significant when using the continuous method. These findings suggest that all reported Type D effects based on personality groups should be reconsidered using the continuous method.