One of the most basic characteristics of a community's social structure is the proportion of its residents who are acquainted with one another-in the terminology of this paper, the community's "density of acquaintanceship." Although versions of this variable have been discussed for at least three-quarters of a century, quantitative studies have found little evidence that it has any significant consequences for psychosocial adjustment. Using a different focus, however, may lead to different conclusions. Drawing from a study of rapid community growth, this paper reports that a marked decline in the density of acquaintanceship did in fact lead to significant consequences-but that the effects were strongest in areas other than psychological functioning. Changes were particularly evident in control of deviance, socialization of the young, and care for the community's weaker members. psychosocial impacts, by contrast, were lessened by the continuing vitality of intimate social supports. The paper concludes that the density of acquaintanceship variable warrants systematic but refocused investigation in the future.