Study on the Typology of Temperament of Japanese Children Aged 3 and 4

Background: Differences between children appear very early in life. One such difference is children’s
temperament. It has been an important clinical and research issue. However, the definition of
temperament is debatable: Many researchers have defined it differently. Whereas the majority of
studies on temperament are variable-centered, temperament structure has rarely been challenged
from a person-centered perspective (i.e., typology of temperament). The purpose of our study is to
identify temperamental typology of Japanese toddlers using the EASI survey and a two-step cluster
analysis.
Methods: Net-survey collected data from 531 mothers and 369 fathers of a 3- or 4-year-old child in
Japan. They were distributed the EASI with 4 subscales (Emotionality (E), Activity (A), Sociability (S),
and Impulsivity (I)) and the Child Behavior Checklist (CBCL).
Results: A two-step cluster analysis yielded 4 clusters: The first cluster (n = 288) was characterized
the highest S and mildly high A and I, and thus interpreted as Average-Active. The second cluster (n =
179) was low in E, A, and I, but mildly high in S, and thus interpreted as Regulated. The third cluster
(n = 288) was almost the same level in I and E as the first cluster, but mildly low in A and S, and thus
interpreted as Average-Quiet. The fourth cluster (n = 145) was high in E, A, and I, but low in S, and
thus interpreted as Sensitive/Hyperreactive. Regulated children scored the lowest in internalizing and
externalizing behaviors on the CBCL subscales whereas Sensitive/Hyperreactive children scored the
highest on these subscales.
Conclusion: The identification of such groups could help us to select different parenting or
intervention strategies based on typology. It has been known that children’s temperaments and
parenting behavior independently influence one another. We identified four typologies of children’s
temperament patterns interpretable as Average-Active, Regulated, Average-Quiet, and
Sensitive/Hyper-reactive. To the best of our knowledge, this study is the first temperament typology
study in a large population of Japanese children.