This study aimed to investigate (1) the reliability and validity of the Taiwan Birth Cohort Study-Developmental Instrument (TBCS-DI) 8-year-old scale; (2) the pathway relationship among the cognitive, emotional and social-communication dimensions of the TBCS-DI 8-year-old scale; (3) the predictive validity and association of the TBCS-DI dimensions at 6, 18, 36, and 66 months, with the dimensions of the 8-year-old scale. The Taiwan Birth Cohort Study dataset of 19,516 children followed from 6 months to the age of eight was used. The TBCS-DI 8-year-old scale showed good reliability and validity. A recursive relationship of emotion as the basis, affecting cognition and later social communication was found. Children’s 18-month development was able to predict the development of children at 8 years, implying that 18 months may be a critical age for screening and intervention. Clinical intervention should also take into consideration the cultural disparity of emotional development in Asian countries.
