Self-descriptions of emotions in 72 participants aged 10 to 77 were assessed. Responses were reliably scored in terms of a 4-level cognitive-developmental coding scheme for each of 4 emotions: anger, sadness, fear, and happiness. Results showed that those younger or lower in ego level and verbal ability described emotions in terms of sensorimotor actions, outer appearance, conventional and technical descriptions, rigid impulse monitoring, and an emphasis on control and the ideal. Those older or of higher ego level and verbal ability conveyed a vivid sense of the experience, had explicit knowledge of bodily sensations, accepted conflict within self and others, and displayed flexibility and delay of action. These findings suggest that understanding of emotions develops along a dimension of cognitive complexity over the life span. This dimension, in turn, is related to life span changes in coping and defense.