Relationship between vocalizations and head nods as listener responses.

An earlier study showed that listeners in conversations insert brief responses ("mm-hmm," "I see," and the like) almost exclusively at the ends of rhythmical units in the talker's speech (Dittmann & Llewellyn, 1967). In this study these vocal responses were compared with a visible one, the head nod, and it was found that the 2 occurred together more often than chance would predict. Content analysis showed that these co-occurrences usually serve an interpersonal function: the wish of the listener to speak or the wish of the talker for feedback. When they did occur together, nods were found to precede the vocal response slightly. Apparently the listener must hold a vocal response politely until the speaker has finished a unit, but may nod before then.