Inquiry about the experience, expression, physiological correlates, and neurological mechanisms of emotion is often shaped by semantics and embedded in elaborate theoretical frameworks. What, for example, are the criteria for emotions and facial expressions? What is the function of a smile? The present exploration of yawning, laughing, smiling, tickling, and talking avoids these issues, at least at the outset. This research observes spontaneous social behavior of people or animals in natural settings, sometimes recruiting subjects to keep logs of their ongoing behavior or retreating to the laboratory to test hypotheses. Social behavior is defined here as acts that are either evoked by or performed primarily in the presence of other individuals. This behaviorally oriented description of the who, where, when, what, and how of ongoing, overt behavior is an underused approach in human social science that produces data that can outlive the propositions that inspire it. Data from this basically atheoretical, descriptive research provide insights into topics ranging from the social role of facial actions (yawning and smiling), vocalizations (laughing and talking), and touch (tickling) to the neurological mechanisms of laughter and speech. Such descriptions of motor acts are the starting point for ontogenetic and phylogenetic analyses, and they provide a bridge between the study of human and animal social behavior (Provine, 1996a, c). Although the movements of organisms (including vocalizations) differ in their complexity, choreography, and motor control, at their root all are muscle contractions triggered by motor neurons. What sets the present set of behaviors apart from walking or breathing is that all are motor acts that in different ways, and to varying degrees, evolved to change the behavior of others.