Genesis and evolution of behavioral disorders: from infancy to early adult life.

The New York Longitudinal Study has followed the behavioral development of 133 subjects from early infancy to early adult life. Special attention has been given to the systematic clinical evaluation and follow-up of all subjects presenting any evidence of behavior disorder. The authors present incidence and outcome data, define the concept of temperament, and briefly discuss conceptual issues and empirical findings. They found the "goodness of fit" (consonance between the individual and the environment) concept useful in tracing developmental sequences. The authors summarize quantitative analyses identifying significant group correlations between antecedent variables and early adult outcome and suggest a tentative classification of the idiosyncratic factors also evident in the clinical course of individual subjects, with case illustrations.