The history of attempts by psychologists to determine the contribution of personality to intelligence has not been one of unqualified success. Part of the problem may be in the balance of granularity of analyses on the intelligence side and the personality side. A comprehensive analysis of the contributions of extraversion and neuroticism to problem solving latency, accuracy, and persistence in stressed and unstressed conditions was undertaken. Two directional predictions were made based on previous research: (1) Solution-time will be shorter in extraverts than ambiverts or introverts, and shorter in ambiverts than introverts, in both stressed and unstressed conditions. (2) Neuroticism will be related to solution-time such that in the stressed condition, mid-neuroticism subjects will be faster than either high- or low-neuroticism subjects who will not be different from each other, and in the unstressed condition high-neuroticism subjects will be faster than mid-neuroticism and low-neuroticism subjects, and mid-neuroticism subjects will be faster than low-neuroticism subjects. Subjects were university students in undergraduate and graduate educational psychology classes. The personality dimensions of extraversion-introversion and neuroticism were measured by Form A of the Eysenck Personality Inventory (EPI). The dependent variables of problem-solving latency, accuracy, and persistence were measured by the Nufferno Tests. Results are discussed in relationship to previous studies. (Author/BJG)