The proposed factor structure of temperament and personality in Japan: combining traits from TEMPS-A and MPT

In Japan, Kraepelin's descriptions on four "fundamental states" of manic depressive illness, the concepts of schizoid temperament by Kretschmer and obsessional and melancholic type temperament by Shimoda and Tellenbach have been widely accepted. This research investigates the construct validity of these temperaments through factor analysis.

TEMPS-A measured depressive, cyclothymic, hyperthymic and irritable temperaments and MPT rigidity, esoteric and isolation subscales measured, respectively, melancholic type and schizoid temperaments. Factor analysis was implemented with TEMPS-A alone and TEMPS-A and MPT combined data.

With TEMPS-A alone analysis, Factor 1 included 1 depressive, 11 cyclothymic and 12 irritable temperament items with a factor loading higher than 0.4; Factor 2 included 1 depressive and 10 hyperthymic temperament items; and Factor 3 included 2 depressive temperament items only. With TEMPS-A and MPT combined data, Factor 1 included 3 depressive, 11 cyclothymic and 5 irritable temperament items with a factor loading higher than 0.4 (interpreted as the central cyclothymic tendency for all affective temperaments along Kretschmerian lines and accounting for 11.7% of the variance); Factor 2 included 6 hyperthymic temperament items (6.22% of variance); Factor 3 included 1 cyclothymic, 7 irritable and 1 schizoid temperament items (interpreted as the irritable temperament and accounting for 3.24% of the variance); Factor 4 included 1 depressive temperament and 5 melancholic type items (interpreted as the latter, accounting for 2.66% of the variance); Factor 5 included 5 depressive temperament items, along interpersonal sensitivity and passivity lines, and accounting for 2.31% of the variance; and Factor 6 included 4 schizoid temperament items accounting for 2.07% of the variance.

We did not use the Kasahara scale, which some believe to better capture the Japanese melancholic type. Sample was 70% male.

These analyses confirm the factor validity of depressive, hyperthymic, cyclothymic and irritable temperaments (TEMPS-A), as well as the melancholic type and the schizoid temperament (MPT). Traits of the depressive and melancholic types emerge as rather distinct. Indeed, our results permit the delineation of an interpersonally sensitive type that "gives in to others" as the core features of the depressive temperament; this is to be contrasted with the higher functioning, perfectionistic, work-oriented melancholic type. Mood dysregulation is represented by the largest number of traits in this population. Contrary to a widely held belief that the melancholic type with its devotion to work and to others is the signature temperament in Japan, cyclothymic traits account for the largest variance in this nonclinical population. Hyperthymic temperament, melancholic type and schizoid temperaments appear largely independent of mood dysregulation. In this Japanese population, TEMPS-A may identify temperament constructs more comprehensively when implemented with melancholic type and schizoid temperament question items added to it. The proposed new Japanese Temperament and Personality (JTP) Scale has self-rated items divided into six subscales.