Smiling:Positive and Negative Emotions, Personal and Social Attitudes

Human smiling has many meanings and functions. In this paper we describe the main components of smiles which are supposed to represent either positive or negative emotions as well as social attitudes. The studies of the French anatomist Duchenne, and the descriptions of Ekman and Friesen are presented here together with a series of studies we have made over many years. Emotional and social aspects of human smiling are discussed not necessarily in terms of opposition but in a new light which takes into consideration part of smiling expression within the realm of a multipurpose meaning of human smiling. According to our point of view adaptive and communicative needs which are often behind smile expressions can belong to a common milieu that can be predictive of social behaviours and rules as well as individual differences according to different cultural contexts.