Vaillant proposes a hierarchy of adaptive ego mechanisms based on his impressive thirty-year follow-up study of thirty men. From a larger sample of two hundred and sixty-eight college men, thirty were selected for study. These men were contacted every two years by questionnaires, autobiographical questions, and occasional interviews. Episodes of behavior, called 'vignettes', were judged by the author to represent a life style and/or ego mechanism of defense. Each vignette was classified by the author according to his list of eighteen mechanisms of defense. An independent rater classified and scored the thirty subjects on an adjustment score, using the questionnaire answers regarding health, marriage, and occupation (position and income). 'Neurotic' defensive styles such as repression, isolation, and displacement were frequently used by all of the men. Vignettes illustrating 'immature' mechanisms were noted nine times less frequently among the eight men with the 'best' adjustment as among the ten men