Development of a Japanese version of the Psychological Ownership Scale

The present study addresses the need for a valid instrument for measuring dimensions of psychological ownership, including that of owned and non-owned objects, for use in the language and culture of Japan. Although the theory of psychological ownership has expanded self-extension theory, the most widely used scale of psychological ownership does not measure the extent to which one feels that it (the owned object) is a part of them. Thus, the present study aimed to develop a Japanese version of the Psychological Ownership Scale (POS-J) and examine its reliability and validity. Study 1 measured the POS-J of an owned object, finding the POS-J to have a two-factor structure (possession-self link and feeling of ownership) and its internal consistency and reliability to be adequate. Moreover, POS-J scores were positively correlated with perceived control and self-extension tendency, but not monetary value, indicating that conceptual validity was generally supported. To confirm whether the POS-J could be used for a non-owned object, Study 2 rephrased the expressions of item descriptions and examined the effect of imagining touching a non-owned object on the POS-J scores, showing that doing so increased the POS-J scores for the object. Our findings suggest that the POS-J is a reliable and valid measure of the psychological ownership of owned and non-owned objects for use in Japan.