Examined the number and nature of temperamental types in 488 children, age 3 years 6 months. Configural-frequency-analysis methods showed clear support for two temperament types: controlled-nonexpressive and noncontrolled-expressive. These types showed meaningful differences against external criteria related to a wide range of problem behaviors.…

Observed 193 children at 4.5 years who had been classified at 4 months as high or low reactive to stimulation for signs of inhibited or uninhibited behavior. Children classified as high reactive were less spontaneous and less sociable than low-reactive children, but only a small proportion maintained a consistently inhibited or uninhibited…

The Fullerton Longitudinal Study is a contemporary prospective investigation that spans approximately a quarter of a century. Commencing at age 1, children and their families were systematically followed every 6 months from infancy through preschool and annually at ages 5 through 17. They were again assessed at age 24. The course of development…