Associations between the number of siblings, parent-child relationship and positive youth development of adolescents in mainland China: A cross-sectional study

Background Positive development plays an important role in youth when dealing with stressful circumstances. According to the resource dilution theory, adolescents with or without siblings may receive different levels of emotional and material resources from their parents. The purpose of this study is to examine the association between the positive development of adolescents in China today with their family characteristics such as the number of siblings. Methods A total of 2072 junior high and senior high school students (13 to 18 years old) in Chengdu, Sichuan, China, were investigated by cluster sampling. The Chinese Positive Youth Development scales (CPYDs) were used to measure positive youth development. The generalized linear model was used to explore the relationships among the number of siblings, parent-child relationships and positive youth development. Results Adolescents from only-child families had better performance on positive development (H = 21.87, P < 0.001) and better relationships with parents (H = 15.1, P < 0.05). The positive development of male and female adolescents does not significantly differ in families with different numbers of siblings. The generalized linear model showed that a positive parent-child relationship is positively correlated with adolescent positive development (P < 0.05). Conclusion Positive youth development is not only associated with the number of siblings but also other modifiable familial factors. The positive relationship between parents and adolescents is of great practical value in daily life to improve youth development, and this might be the real lesson the resource dilution theory tells.