Psychometric properties of the Polish version of the Self-Pluralism Scale (SPS).

Background: The Self-Pluralism Scale (SPS) measures the declared degree of self-pluralism, visible already in William James's works. Self-pluralism refers to the degree to which one perceives oneself as typically feeling, behaving, and being different, in different situations, and at different times. The purpose of the current study was to evaluate the psychometric properties of the Polish version of the SPS.

Participants and procedure: A total of 1747 participants (67% were women) between the ages of 15 and 70 years completed the SPS along with measures of self-concept inconsistency, self-concept differentiation, dissociative experiences, internal dialogical activity, personality, and social desirability.

Results: Internal reliability and test-retest reliability were high. The full version has too low indices of fit whereas the brief, 10-item version fits the data well. As indicators of the convergent validity, a positive correlation of SPS with self-concept inconsistency, self-concept differentiation, dissociative experiences, internal dialogical activity and neuroticism and a negative correlation with agreeableness and social desirability were found.

Conclusions: The results suggest that the brief, 10-item version is more valid than the full, 30-item version. The tool may be used for scientific research concerning self-pluralism. After collecting data from a sample that would allow norms to be constructed, the tool may also be useful for individual diagnosis.