This thesis addresses some systematic differences among people in understanding human behavior. The concepts used are part of Descriptive Psychology, a conceptual system developed by Dr. Peter G. Ossorio.

Ossorio's parametric analysis of behavior is described. The performance parameter (P) and the significance parameter (S) are used to generate the concepts of a performance-oriented person (P-type) and a significance-oriented person (S-type). A P-type is a person who emphasizes the performance or process aspects of behavior, and is somewhat lacking in appreciation of significance or meaning. An S-type is a person who is not deficient in appreciating significance. Previous research is cited which explores differences between P-types and S-types in understanding feminine and masculine behavior. This thesis explores differences between P-types and S-types in understanding intrinsic and instrumental behavior.

Instrumental behavior is behavior for a result, the result being the only value of the behavior. Intrinsic behavior is understandable as engaged in for its own sake, without further end in view. An intrinsic social practice is a candidate for a complete behavioral description. In contrast, a description of behavior as instrumental is not a complete description.

Intrinsic social practices organize instrumental behavior and give it meaning. Without intrinsic practices goals would be arbitrary and meaningless. Four types of intrinsic practice are introduced: acting on an interest, acting on a relationship, emotional behavior, and motive pattern behavior. Differences between the Descriptive Psychology approach to intrinsicness and instrumentality and those of other frameworks are pointed out.

The major hypothesis is that S-types appreciate intrinsicness of behavior, while P-types are somewhat lacking in appreciation of intrinsicness and tend to use an instrumental framework. Results lend partial support to the hypothesis. The practices of acting on an interest and acting on a relationship are effective in discriminating the groups in the predicted ways. Results are mixed for emotion and motive pattern behaviors.

The utility of the conceptualization to the psychotherapist is explored, including application to problems of meaning, self-concept, and relation to other psychopathologies. [171 pp.]