The purpose of this study was to examine how children’s extraversion and effortful control temperament
develop from ages 5 to 7, and how this developmental change is associated with their intelligence at age
7. The participants in this study comprised 100 pairs of 5-year-old child and their mothers. The
temperaments of participating children were measured with mothers’ reports at 5, 6, and 7 years of
age, and their intelligence was measured using K-WISC III at the age 7. The effect of the developmental
changes in children’s temperament on intelligence development was investigated by means of latent growth
modeling. According to the results, the ‘extraversion’ temperament was negatively correlated with Verbal
IQ and Performance IQ. The ‘effortful control’ temperament was positively correlated with PIQ and VIQ.
Next, there were individual differences in children’s extraversion at the age of 5, and these individual
differences were also observed in the rate change over the next 3 years. ‘Extraversion’ temperament at the
age of 5 negatively affected both PIQ and VIQ. Lastly, there were individual differences in children’s
‘effortful control’ at the age of 5, and the rate change in ‘effortful control’ from 5 to 7 also showed
individual differences. The rate change of the ‘effortful control’ temperament had a marginally positive
effect on VIQ, and the initial values of ‘effortful control’ had a positive effect on PIQ. Through
longitudinal analyses of relations between children's temperament and intelligence, the study findings
suggest that temperament affects intelligence development.