本研究採用延宕交叉相關與二階層線性成長模式來探討青少年自尊與快樂感間的因果機制及其發展。研究資料係取自「台灣青少年成長歷程研究」，計有台灣40所學校的國一學生，每年追蹤調查一次，共計三波，共2,334位。延宕交叉相關結果發現，快樂感與自尊具有交互影響關係，且快樂感係扮演啟動者的角色。基於此一發現，本研究進一步以階層線性成長模式分析自尊隨時間變化之趨勢與成長速率，並探究性別與快樂感對對自尊的起始狀態與成長速率的影響。結果顯示：(1)自尊的起始狀態與成長速率呈現負相關，亦即國一時自尊較高者，以後每年的自尊成長率有較低之傾向；(2)女孩與男孩的自尊在中學階段均隨著年齡的增長而下降，且女孩的下降幅度更大；(3)快樂感對於青少年自尊的起始狀態與成長速率具有解釋力。本研究的發現對於台灣青少年自尊的發展研究具有重大突破，並提出輔導實務與後續研究之相關建議。

This study investigated the causal mechanism and development of happiness and self-esteem from Grade 7 to Grade 9 by repeated assessment of 2,334 students in 40 junior high schools in Taiwan. Cross-lagged panel correlation analysis showed that happiness played a starting role in the reciprocal relationship between happiness and self-esteem.Then we used hierarchical linear growth model to analyze teenagers’ self-esteem
varying by time and the effects of gender and happiness on the initial status and the growth rate. Results showed that: (1) The correlation between the initial status and the growth rate of self-esteem was negative; meaning that the lower self-esteem students tended to declined faster than that of the counterparts; (2) The growth rate of self-esteem
on Girls declined faster than that of boys; (3) The happiness had effects on the initial status and the growth rate of teenagers’ self-esteem, respectively. These findings have important implications for enhancing development of self-esteem and happiness in adolescents.Suggestions for future studies are also discussed.