Academic Performance of Only Children Who Monopolize Parental Resources

Resource dilution theory suggests that many parental resources are dilutable and thus are responsible for the negative effect of sibship size on educational outcomes. However, the special case of only children has rarely been investigated. Analyzing Taiwan Education Panel Survey (TEPS), this study finds that only children do not quite fit this pattern. Birth order also complicates the picture. Controlling for family socioeconomic status (SES), the majority of firstborns outperform only children in academic performance; other peers from small-sized families fare just as well as only children in spite of their disadvantage in obtaining parental resources. Several related factors have been controlled (including parents’ old age, poor health, marital discords, marital dissolution, and the child’s developmental problems). As these alternative accounts have been ruled out, lacking sibling interaction is very likely to be the major cause why only children do not fit the pattern of negative sibship size effect, an association predicted by resource dilution theory.