The Type A personality has been associated with coronary heart disease and other psychosomatic illnesses. Previous investigators have suggested that a major stress-related feature of the Type A personality is "excessive" striving for achievement, even though ambition is often conceptualized as a positive aspect of personality. The purpose of the present dissertation was to examine whether there are psychological differences in how Type A individuals, compared to their Type B counterparts, approach and respond to an achievement situation, which, in addition to defining the Type A personality, have potential pathogenic health and personal adjustment implications. Three experiments are reported which examined self-directed behavior in an achievement situation where subjects were required to perform sequential general information tests. The results of Experiment I support the hypotheses that Type A individuals, compared to Type B individuals, adopt very high standards for performance, which increase the probability that they will not achieve their personal goals. The results of Experiment II expand on the findings of Experiment I by indicating that in addition to not achieving personal goals, Type A individuals, relative to Type B individuals, also tend to devalue their actual performance. Furthermore, failure to achieve personal goals was associated with increased self-report of psychological distress. The findings of Experiment III replicate previous results and further indicate that failure to achieve personal goals is associated with specific negative consequences of increased anger and decreased self-esteem. The results also indicate that Type A individuals compared to Type B individuals, tend to make internal attributions for failure, while at the same time, they take less personal credit for success. Finally, the results of Experiment III suggest that the Type A personality is related to general negative affective states, psychosomatic illness, and daily stress. Results of the three experiments indicate that there are important psychological characteristics of how Type A individuals approach and respond to an achievement situation, which appear to have pathogenic health and personal adjustment consequences. Recent reconceptualizations of the Type A personality have emphasized a trait-like dimension of hostility, characterized by cynicism, resentment, and suspiciousness toward others as the "toxic" component of the Type A personality. The present study urges that striving toward lofty goals, devaluation of performance, self-blame for failure without taking comparable self-credit for success, along with negative self-evaluation also be viewed as important unhealthy aspects of the Type A personality. / Ph. D.