CHAPTER II.

THE SMILE AND THE LAUGH.

Need of studying the bodily process in laughter • 25

Characteristics of the movements of the smile • 26

Expressive function of the smile • 27

Continuity of processes of smiling and laughing • 27

Characteristics of the movements of laughter • 30

Concomitant organic changes during laughter • 33

Physiological benefits of laughing • 34

Effects of excessive laughter • 37

The laugh as expression • 39

Relation of expression to feeling in laughter • 40

Interactions of joyous feeling and organic concomitants • 44

Deviations from the normal type of laugh • 48