Facial asymmetry in emotional expression: A meta‐analysis of research

A meta‐analysis of 65 hypothesis tests in 14 published studies of asymmetry in the facial expression of emotion is reported. The analysis examines which side of the face has been found more strongly to express emotion as well as the effects of three moderator variables: (i) the type of expression; (ii) the method of eliciting the expression (posed or spontaneous); and (iii) dimensions of emotional experience. The analysis reveals a highly significant but small effect for the left side of the face to be judged more expressive than the right. Additionally it reveals that asymmetry is ( a ) stronger for emotional than neutral expressions, ( b ) stronger for posed emotional expressions compared with spontaneous emotional expressions and ( c ) predicted by some dimensions of emotional experience, notably pleasantness. The results highlight theoretical and methodological issues in asymmetry of facial emotional expression.