Tom Postmes

Who they are

Tom Postmes is a social psychologist. His work on this site is the 2013 paper written with S. Alexander Haslam and Lise Jans, published in volume 52, issue 4 of the British Journal of Social Psychology.

Key papers

• Postmes, T., Haslam, S. A., & Jans, L. (2013). A single-item measure of social identification: Reliability, validity, and utility. British Journal of Social Psychology, 52(4), 597-617.

The paper introduces a one-item measure in which respondents rate on a seven-point scale how far they agree that they identify with their group or category. Three studies examine its convergent, divergent and test-retest validity across a wide range of social groups. The authors also pooled sixteen commonly used single-item measures and report that their reliability ranged from low to reasonably high, with the new item high by comparison.

Key ideas

The paper argues that short measures tend to struggle when the construct is broad and mixed, and that social identification appears uniform enough to be captured by a single item. It is one of the positions in the measurement literature on group identification, set against multi-part approaches such as the hierarchical multicomponent model.

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