A paper by Associate Professor Shuhei Iimura of the Faculty of Education has been published in an international academic journal.

A paper by Associate Professor Shuhei Iimura of the Faculty of Education, titled "Psychometric properties of the Highly Sensitive Child Scale and its role in socio-emotional and behavioral development: Evidence from Japanese adolescent samples" (Note 1), was published on September 22, 2026, in the international academic journal "Journal of Personality Assessment" (Note 2).

In studies 1 and 2, we translated the revised 21-item Highly Sensitive Child scale, which measures trait sensitivity (Note 3), into Japanese and examined its psychometric properties (N = 1,343 mothers and children). This scale is self-reported by adolescents aged 10 to 14, and assesses 21 items such as "I get tired easily in crowded places," "Loud noises make me feel uncomfortable," and "I can immediately recognize what a smell is" on a 7-point scale from "strongly disagree (1 point)" to "strongly agree (7 points)."

Study 3 used longitudinal survey data from three time points to investigate how baseline trait sensitivity and each environmental factor (quality of care, peer relationships) are related to adolescent developmental outcomes (internalization, externalization, prosocial behavior) (N = 1,032 mothers and children). The results showed that trait sensitivity and each environmental factor were related. Rather than acting in an interacting manner, it was suggested that each factor is additively associated with developmental outcomes. In particular, The study showed that higher trait sensitivity was associated with a greater tendency towards internalization problems (such as depressive symptoms and anxiety) and prosocial behavior. Given the positive correlation with both negative and positive developmental outcomes, it suggests that high trait sensitivity may be a "plasticity factor" rather than simply a "vulnerability factor."

(Note 1) This paper is an international collaborative research project involving Lecturer Kosuke Yano and Professor Chieko Kibe of Toin Yokohama University, Researcher Sofie Weyn of the University of Bern (Switzerland), and Professor Michael Pluess of the University of Surrey (United Kingdom).
(Note 2) The *Journal of Personality Assessment* is an international journal that covers research findings on psychopathology and personality assessment. Scopus CiteScore is ranked within the top 20% (Q1) in the clinical psychology field and is one of the top journals in the field of personality assessment.
(Note 3) Here, trait sensitivity refers to temperament and personality traits that explain individual differences in susceptibility to both negative and positive environmental stimuli. For more details, please visit the website "Japan Sensitivity Research" (https://www.japansensitivityresearch.com/) run by Associate Professor Iimura.

■ Paper Information
Iimura, S., Yano, K., Kibe, C., Weyn, S., & Pluess, M. (2026). Psychometric properties of the Highly Sensitive Child Scale and its role in socio-emotional and behavioral development: Evidence from Japanese adolescent samples. Journal Personality Assessment.

■Journal article page
Full article: Psychometric Properties of the Highly Sensitive Child Scale and Its Role in Socio-Emotional and Behavioral Development: Evidence from Japanese Adolescent Samples

Associate Professor

Shuhei Iimura

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Specialized Field

Developmental Psychology, Adolescent Psychology

Research theme

Clarification of the mechanisms of individual differences in psychosocial development based on environmental sensitivity theory