The purpose of this study was to investigate the personality differences between identical twins that their mothers perceive, and characterize the mothers who subjectively create either more or less personality differences between them. In Study 1, fifty-four mothers with three to six year-old twins (37 identical and 17 fraternal) filled out a questionnaire. In Study 2, ten twin mothers (7 identical and 3 fraternal), who also participated in Study 1, underwent semi-structured interviews. The main findings were as follows: Identical twin mothers perceived personality differences of their twins according to their birth order, while fraternal twin mothers did not. And those identical twin mothers who perceived more personality differences between their twins tended to describe each with more personality terms and daily behaviors, when characterizing each twin. On the other hand, those identical twin mothers who saw less personality differences inclined to contrast the twins each other, and describe each with fewer personality terms.

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The purpose of this study was to examine the relationship between Eysenck's personality dimensions and conditionability in verbal respondent conditioning. EPI was administered to 705 students, and 42 subjects with extreme scores and 13 with moderate scores were selected. They were assigned to four groups: 12 stable extraverts, 15 stable introverts, 15 neurotic introverts, and 13 ambiverts. Nonsense syllables as CS were paired with words with various affective tones. After a conditioning session using 15 CS-UCS pairs, all subjects were asked to recall the nonsense syllables, and estimate their affective tones. The number of syllables recalled and rated affective tones were used as indices of conditionability. The results showed that when negative words were used as UCS, introverts were more readily conditioned than extraverts. However, no significant relationship between neuroticism and conditionability was found.

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The purpose of the present study was to construct a reliable and valid psychological scale of interpersonal trust, and examine the relationship between interpersonal trust and the earliest recollection (ER). In Study 1, high school and college students, 538 in all, filled a questionnaire, and a l7-item Interpersonal Trust Scale (ITS) was constructed. The scale had high internal consistency and test-retest reliability. In Study 2, data from 523 high school and college students showed meaningful correlations between ITS and several conceptually-related personality scales, suggesting its validity. In Study 3, the relationship between the ITS score and ER was examined with the data of 488 college undergraduates, who gave answers to an open-ended questionnaire. The result showed that students with high ITS scores remembered significantly more positive feelings and less negative feelings for their ER than those with low ITS scores. It was also found that interpersonal trust was related to feelings attached to human figures in ER.

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A time-series analysis tested the hypothesis that social support both reduces stress and enhances self-esteem, and thus decreases anxiety. The relationship between support types and adjustment types was also examined. One hundred thirty-five freshmen, who had both parents and at least a sibling, participated in the study. They filled out a questionnaire four times (in April, June, September, and December), which measured social support received from family members, same-and opposite-sex friends of both pre- and post-admission, a romantic partner, an older student, and a professor. Scales also measured stress, self-esteem, and anxiety. Path analysis showed that with minor variations, support from same- and opposite-sex friends of both pre- and post-admission enhanced self-esteem and thus reduced anxiety. Cluster analysis on social support scales revealed eight types: dependent (on pre-admission friends and post-admission same-sex friends), sociable, solitary, and so on. Six types were also found in relation to stress, self-esteem, and anxiety: consistent over time (on the three), emotionally unstable, emotionally stable, and so on. The solitary type was found to be emotionally unstable.

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Furukawa Takeji (1891-1940) proposed a theory on the relation between blood types and temperament. In this paper, we attempted to describe why and how he developed the unique theory, in the context of education during the late Taisho-early Showa period (1920s). First, a few formative influences on Furukawa's life and career were reviewed, and some of his early articles examined, which were written prior to his theory on temperament. There are three facts that we found especially interesting and informative. (1) Furukawa majored in experimental education at university, and upon his employment at a women's high school, he worked in its administration office. He came to believe there that temperamental differences of applicants were responsible for the failure of predicting school performance from results of entrance examination. (2) He thought that human temperament was so simple that a theory needed to consider only two temperament types. (3) He was from a family of many doctors, and was familiar with blood type, which was the newest physiological discovery of the day. In conclusion, the significance of studying history of psychology was discussed.

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With ideas and suggestions from Kurt Lewin's approach to psychology (1935), a new approach to personality psychology is proposed. It is argued that models of internal processes and their parameters should be central for our understanding of personality. Kurt Lewin's view of human behavior as a function of the person and situation is described and named here as process interactionism. Personality variables of our new paradigm are person and process variables. Person variables are indices of internal individual differences, and process variables are those measured to tap the processes within the person that reflect situational changes postulated in Lewin's interactionism. The variables then are analyzed to examine possible mediational and moderational models. Finally, self theories in the framework of 'social psychology of self process' (Nakamura, 1990) are reviewed, and their characteristics and limitations discussed. It is suggested that we need models of internal motivational and self-regulatory processes in order to understand the self in particular, and our personality in general.

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