Good hand, bad hand: correlations between gesturing hand and speech valence

There is general agreement that the body expresses emotion, and while there is research on the expression of emotion in so-called “body language” (e.g. facial expression, posture), only little research exists on the expression of emotion in hand gestures. Two previous studies (Casasanto & Jasmin, 2010; Kipp & Martin, 2009) found opposing patterns of correlation between the gesturing hand and the valence of the co-occurring speech, and this thesis aims to help fill the research gap with the help of two empirical studies, the first on gesture production and the second on gesture perception, both in relation to valence. The first study analyses the handedness of gestures and valence of speech produced by three guests on the Tavis Smiley Show. For two of the three speakers it was found that gestures produced with the dominant hand tended to co-occur with positive speech, while gestures produced with the non-dominant hand tended to co-occur with negative speech, a pattern similar to that found by Casasanto and Jasmin (2010). No pattern of correlation was found for the third speaker. The second study used an experiment to explore whether the handedness of gesture affect the valence ratings of co-occurring speech, using systematically varied video data of one-word utterances and pragmatic gestures. This study found some evidence that words co-occurring with gestures performed with the right hand receive higher valence ratings, while words co-occurring with gestures performed with the left hand receive lower valence ratings, with a larger effect for negative words than positive words. In sum, this thesis supports previous findings of correlations between the handedness of gestures and the valence of speech in production, but also shows inter-individual variation and points out the need to consider demographic factors in future research. It found some evidence of the effect of handedness of gesture on the perceived valence of speech, but more research is needed, and should include left-handed participants and speakers to determine the pattern of correlation between handedness of gesture and speech valence