Forty-four participants were asked to sing moderate, high, and low
pitches while their faces were photographed. In a two-alternative forced choice task,
independent judges selected the high-pitch faces as more friendly than the low-pitch
faces. When photographs were cropped to show only the eye region, judges still rated
the high-pitch faces friendlier than the low-pitch faces. These results are consistent
with prior research showing that vocal pitch height is used to signal aggression (low
pitch) or appeasement (high pitch). An analysis of the facial features shows a strong
correlation between eyebrow position and sung pitch—consistent with the role of
eyebrows in signaling aggression and appeasement. Overall, the results are consistent
with an inter-modal linkage between vocal and facial expressions
