Positive and negative: Infant facial expressions and emotions

One path to understanding emotional processes and their development is the investigation of early facial expressions. Converging evidence suggests that although all infant smiles index positive emotion, some smiles are more positive than others. The evidence stems both from the situations in which infants produce different facial expressions and from naive observers' ratings of the emotional intensity of the expressions. The observers' ratings also suggest that similar facial actions-such as cheek raising-lead smiles to be perceived as more positive and lead negative expressions (cry-faces) to be perceived as more negative. One explanation for this parsimony is that certain facial actions are associated with the intensification of both positive and negative emotions.