An EMG-based approach toward the assessment of implicit self-esteem

An important aspect of implicit self-esteem is the positivity of peoples spontaneous affective reactions to the self. In this study, we developed and validated a physiology-based measure that captures such positive reactions. We presented participants (N = 256) self-related stimuli (i.e., pictures of themselves) and used electromyography (EMG) to record changes in facial muscular activity that are indicative of subtle smiling. EMG responses were on average positive, which matches with previous research findings on positively biased self-evaluations. Individual differences in EMG responses were moderately reliable and positively associated with explicit self-esteem and self- and peer-rated likability (but not consistently with measures of well-being and agentic behavior). The relations between the EMG responses and likability indicators largely held when we controlled for explicit self-esteem, indicating that the novel measure possessed incremental validity over self-reports. The results thus indicated that the EMG approach might be fruitful for the assessment of implicit self-esteem.