Hemiface mobility and facial expression asymmetry.

Thirty-seven right-handed college-aged males and females were assessed for facial asymmetry during emotional expression and for nonemotional hemiface mobility. Objective, subjective, and undirected measures of facial mobility were obtained, separately for the upper and lower face. While judges rated mobility of the lower face as left-sided, subjects declared themselves to be as facile on the right as on the left side of the face. When asked to move a side of the lower face, subjects moved the right side more frequently than the left. For the upper face, none of the measures of mobility were significantly left- or right-sided. Facial expression asymmetries (which were observed to be left-sided) were not significantly related to any measures of hemiface mobility.