Abstract
Cross-sectional data were analyzed for a possible relationship between household densities and physiologic alteration, based on socialization experiences with siblings in an earlier home environment. The measure of household density was persons-per-room and the measure of physiologic alteration was urinary vanillylmandelic acid. The results show an interaction between number-of-sibs and number-of-younger-sibs, with a statistically significant positive correlation between household densities and VMA values for subjects with fewer total sibs and no younger sibs, while a negative correlation was observed for subjects with one or more younger sibs. One possible interpretation of these results is that the physiologic response to crowding in humans is dependent at least in part on the earlier socialization experiences of the individual.