PURPOSE: Early adolescence is a pivotal developmental stage characterized by rapid physical, emotional, and social changes. Happiness during this period is crucial as it influences later life outcomes. This study examined 4-year changes in happiness and identified predictors among Korean early adolescents. METHODS: A secondary analysis of longitudinal panel data was conducted using latent growth modeling to assess changes in happiness over 4 years, utilizing data from the Panel Study on Korean Children (11th-14th waves) with a total of 1,177 participants. Descriptive statistics were computed using IBM SPSS ver. 29.0, and latent growth modeling, including unconditional and conditional models with associated factors variables, was conducted using IBM AMOS ver. 29.0. RESULTS: A nonlinear trajectory was identified with a sharp decline in happiness, particularly between the ages of 11 and 12 years. Self-esteem, peer attachment, and a creative school environment emerged as protective factors mitigating this decline, whereas parental attachment influenced baseline happiness but not its trajectory. Higher self-esteem, stronger peer attachment, and supportive school environments were associated with a slower decline in happiness. CONCLUSIONS: Our findings highlight the importance of early interventions beginning around the age of 11 years, a critical period when happiness decreases more steeply. Practical implications include developing school-based and psychosocial programs that strengthen self-esteem and positive peer relationships, and fostering autonomy-supportive, creative educational environments. Coordinated efforts between schools and families are essential to promote adolescents' emotional well-being and ensure balanced development in academic and socio-emotional domains.
Jeong et al. (2026) studied this question.