Final answer:
Universal facial expressions are biologically based signals of emotion consistent across different cultures, while nonverbal micro-signals (NMS) are more culture-specific and often unconscious gestures or micro-expressions.
Step-by-step explanation:
Nonverbal signaling mechanisms, such as facial expressions, play a crucial role in interpersonal communication. Noted psychologist Paul Ekman's research has demonstrated that certain facial expressions of emotion are universal across human cultures. These involve innate facial movements that correspond to seven emotions: happiness, surprise, sadness, fright, disgust, contempt, and anger. Ekman's findings suggest a biological basis for these expressions, as they are also present in congenitally blind individuals. However, 'display rules'—the cultural norms dictating the appropriate expressions of emotion—do affect when and how these universal facial expressions are shown. While everyone might recognize a smile as a sign of happiness, cultures differ on whether it's appropriate to smile in certain social contexts or situations. In addition, the concept of 'nonverbal micro-signals' (NMS) might refer to the more nuanced, often unconscious, micro-expressions, gestures, or body language that vary more widely between cultures and are not as universally recognized as the basic facial expressions of emotion that Ekman identified.