Indiana's 92 counties have been described in terms of certain social, cultural and economic variables.1. Spearman Rank-Ordered Correlations of 6 of these variables justified the inclusion of 4 unit variables under a single composite category called the urbanization factor.2. Net population change during the period 1950-1956 was isolated as a distinct variable which correlated at a low but consistent level with urbanization. No significant correlation was noted between a sensitive measure of county educational status (% of those aged 16 to 17 still enrolled in school) and the other social variables studied in the state at large.3. Counties at the extremes of urbanization followed no recognized geographic patterns of distribution. Those counties extreme for negative population shift were generally located at the periphery of the state, while those showing maximum influx of population during the same period tended to be centrally located.4. Counties with the highest percentage still enrolled in school were located in the northern half of the state, whereas, those showing lowest enrollment in school were distributed in the southern half of the state.5. A similar north-south discrimination of counties at the extremes of economic status also was noted.6. An analysis of the independent impact of urbanization on state hospital admission rates, presuming homogeneous distribution of equivalent resources, reveals no differences in admission rates for the 2 groups of counties at the extremes of urbanization. The lack of interaction here may well reflect the fact that the urbanization extremes studied are insufficiently extreme to reveal an independent influence of urbanization, as has been shown in certain previous studies.A similar analysis revealed no significant effect in those counties extreme for population mobility, but did indicate a significant inverse correlation between school enrollment and institutional admission rates.A separate reanalysis of the interaction of these social variables with admission rates for each mental hospital, and its admission zone as a geographic and institutional unit, revealed that zonal admission rates were correlated in highly individual and specific ways with zonal socioeconomic and educational characteristics. A generalization justified by these data is that certain common sociologic variables, even at the extremes of a normal distribution, will find significant expression in their impact on the level of utilization of the state mental institution, only in a highly specific context.Abstract Teaser