Authors: R. Michael Bagby, James D. A. Parker and Graeme J. Taylor
The TAS is a 20-item instrument that is one of the most commonly used measures of alexithymia. Alexithymia refers to people who have trouble identifying and describing emotions and who tend to minimise emotional experience and focus attention externally.
The TAS-20 has 3 subscales:
• Difficulty Describing Feelings subscale is used to measure difficulty describing emotions. 5 items – 2, 4, 11, 12, 17.
• Difficulty Identifying Feeling subscale is used to measure difficulty identifying emotions. 7 items – 1, 3, 6, 7, 9, 13, 14.
• Externally-Oriented Thinking subscale is used to measure the tendency of individuals to focus their attention externally. 8 items – 5, 8, 10, 15, 16, 18, 19, 20.
Scoring: The TAS-20 is a self-report scale that is comprised of 20 items. Items are rated using a 5-point Likert scale whereby 1 = strongly disagree and 5 = strongly agree. There are 5 items that are negatively keyed (items 4, 5, 10, 18 and 19). The total alexithymia score is the sum of responses to all 20 items, while the score for each subscale factor is the sum of the responses to that subscale. The TAS-20 uses cutoff scoring: equal to or less than 51 = non-alexithymia, equal to or greater than 61 = alexithymia. Scores of 52 to 60 = possible alexithymia.
Reliability: Demonstrates good internal consistency (Cronbach’s alpha = .81) and test-retest reliability (.77, p<.01). Validity: Research using the TAS-20 demonstrates adequate levels of convergent and concurrent validity. The 3 factor structure was found to be theoretically congruent with the alexithymia construct. In addition, it has been found to be stable and replicable across clinical and nonclinical populations.
Reference: Bagby, R. M., Parker, J. D. A. & Taylor, G. J. (1994). The twenty-item Toronto Alexithymia Scale-I. Item selection and cross-validation of the factor structure. Journal of Psychosomatic Research, 38, 23-32." Information quoted from Ciarrochi, J. & Bilich, L. (2006). Process measures of potential relevance to ACT. Unpublished manuscript, University of Wollongong, Australia.
Please see http://www.gtaylorpsychiatry.org/tas.htm for additional details.