Three scales of alexithymia: do they measure the same thing?

The psychometric properties of three scales of alexithymia were examined in a sample of 187 female undergraduates. The Shalling Sifneos Personality Scale (SSPS) and the Minnesota Multiphasic Personality Inventory (MMPI) Alexithymia scale had little internal consistency. The scored archetypal test with nine elements (SAT9) had very low interrater reliability. As predicted, the tree measures were not significantly related to one another and the SSPS had a more clearly defined factor structure than the MMPI scale. The MMPI and SSPS scales were differentially related to measures of symptomatology but were similarly related to extraversion, absorption, and SAT scores. Of the three scales, the SSPS appeared to have the highest content validity. The results suggest that alexithymia is not a unitary construct and that its reification as such may be premature.