Fact or artefact: an item response theory analysis of median split based repressor classification

Many studies have investigated the phenomenon of repression. Repressors are defined as individuals who deny or avoid the experience of negative affect. A common method for the identification of repressors is a median split approach using questionnaires that measure anxiety and social desirability. The present study aimed to evaluate this most frequently used procedure using a psychometric model.

We applied item response theory using model assumptions comparable with those of the median split approach to detect repressors and examine the appropriateness of the median split procedure.

A mixed sample of 655 students and members of the general public completed the two scales usually used to identify repressors, namely the Taylor Manifest Anxiety Scale and the Marlowe-Crowne Social Desirability Scale.

Employing item response theory mixture-model analyses, we were unable to replicate the median split solution on a latent level.

Our results did not support the identification of repressors via dichotomization of the two scales. The median split approach does not appear to detect repressors satisfactorily. The implications of the results for the conceptualization and assessment of repressors are discussed.