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1 I should like to thank Erik Van Hove, whose terse and effective criticism of the field helped me avoid employing anthropomorphic formulations of collective behavior. I am also thankful to Ralph Hingson for his insightful discussions of the issues and to James S. Coleman for his criticism of an earlier version of this paper. I am especially grateful, moreover, to Jo Anne Earp and Linda Gottfredson whose substantive contributions and intensive editing have greatly increased the clarity of the paper. The author, however, bears full responsibility for the ideas as expressed.
Paul White (Sun,) studied this question.