本研究發現背景對青少年學生學業成就之因果機制如下：在家庭背景方面，父母教育程度較高者，其父母教育參與較多、補習多及教育物質資源較豐富，使其學業成就較高。在家庭結構方面，單親者及無親者父母教育參與少，而無親者補習、教育物質資源較少、自我教育期望較低，使其學業成就較差；手足數目多者，不良嗜好多、教育物質資源少，使其學業成就較差。在都市化程度方面，居住在鹿野鄉者父母教育參與較少、不良嗜好較多、教育物資資源較缺乏，使其學業成就較差。 在族別方面，關山地區原住民國中生在平均學業成就或主科成續的整體表現均比漢族國中生差。但在控制背景、中介變項後，原、漢族別平均學業成就的差異消失了。造成原漢平均學業成就差異的原因是：原住民學生父母教育參與較少、教育物資資源較缺乏，使其學業成就較差。除些之外，原住民學生在背景變項上就比漢人學生差，如：原住民就讀學校都市化程度較低、父母教育程度比漢人低，雙親比例比漢人低、單親和無親比例比漢人高，手足數目比漢人多。這些背景變項比漢人差，在前述的文化資本、社會資本及財務資本等中介變項也就較差，使原住民學生的成績不如漢族學生。 另外，經貫時性資料分析，發現飲酒行為會影響學業成就，而原住民學生的飲酒行為比漢人學生多，因為過量飲酒除了會造成腦部傷害，也會耽誤溫習功課的時間，使原住民學生的成績更不如漢族學生。

This research finds that the casual mechanisms of background factors affecting juvenile academic achievement are as follows：In the family background aspect, the more parental education, the more parental involvement, the more shadow education and the more educational resources, the more academic achievement can be improved. In the family structure aspect, in a single parent or no parent family, the less parental involvement, the less shadow education and fewer educational resources, fewer educational aspirations, the worse the academic achievement. In the sibling numbers aspect, the more siblings, the more bad habits, the fewer educational resources, the worse the academic achievement. In the urbanization aspect, living in Lu-Yeh County, the less parental involvement, the more the bad habits, the fewer educational resources, the worse the academic achievement. In the ethnic aspect, the Aborigines’ academic achievement in the Qun-san area is worse than the Hans’. But after controlling the background and intervening variables, there is no difference between Aborigines and Hans. The factors causing differences between Aborigine and Han academic achievement are：The Aborigines’ parental educational involvement are significantly less than the Hans’； The Aborigines’ negative habits (culture capital ) are significantly more than the Hans’；The Aborigines’ shadow education and educational resources are significantly less than the Hans’. In addition, the Aborigines’ backgrounds are worse than the Hans’. For example, the Aborigines living in low urbanized areas, parental education is less than 2.5 years than the Hans, the intact family proportion is less than the Hans, the single parent family and no parent family proportion are greater more than the Hans, the numbers of siblings are more than the Hans. These backgrounds cause less parent educational involvement, more negative habits, less financial capital, thus reducing the Aborigines’ academic achievement. According to a longitudinal data analysis, drinking behavior affects academic achievement；academic achievement has no effect on drinking behavior. Drinking behavior is an important reason the Aborigines’ academic achievement is below the Hans’, besides the above reasons.