The purpose of this study was to develop a test which would reveal a person's primary level of existence according to Clare W. Graves' model of adult psychosocial behavior. The sub-purposes of this study were (1) to translate Graves' theoretical levels of existence into discrete components of attitude and behavior which could then be assessed with a written test instrument, (2) to create such a written instrument, and (3) to test the instrument for reliability and validity. The general conclusion of this study is that the Levels of Existence test meets the standards of reliability and validity accepted within psychometrics sufficiently to recommend that it be revised with respect to certain details as specified in the study, and that further research be undertaken.