Four studies were conducted to examine three issues: (1) the relationship between spatial and verbal ability, (2) the relationship between spatial ability and social intelligence, and (3) sex differences in the relationship between spatial and verbal ability. Contrary to the traditional assumption that all abilities exist in a "positive manifold" (Thurstone, 1934, 1935) but consistent with previous research on strategy usage and with correlational data, no relationship was found between spatial and verbal ability for the population of individuals who have high spatial ability. Similarly, no relationship was found between spatial ability and social intelligence (as measured by Missing Cartoons) for the population of individuals who have high spatial ability. Third, no evidence was found for sex differences in the relationship between spatial and verbal ability. This result is contrary to the implications of Ozer's (1987) and Sherman's (1967, 1978) explanations for the sex difference in spatial ability, but consistent with previous correlational data and investigations of sex differences in the strategies used to solve spatial problems.