Abstract
Population aging has become a common problem all over the world, and the process of China's population aging is developing rapidly. China has made active aging a national development strategy, giving full attention to the physical and mental health of the elderly. Bloodline and family continuity make the Chinese elderly attach great importance to the responsibility of caring for grandchildren. This study takes the elderly as the research center, and aims to investigate the relationship between caring for grandchildren and the mental health of the elderly in China, and whether participation in social activities mediates such an association. Adopting the data from the 2018 China Health and Retirement Longitudinal Study (CHARLS), a Chi-squared test and multiple regression results showed that caring for grandchildren significantly improved the mental health level of the elderly in China, and the results were still valid after the use of the Propensity Score Matching (PSM) to solve the endogenous problems. Analysis of the mediating effects using the Structural Equation Model (SEM) showed that caring for grandchildren indirectly contributed to the reduction of depression by increasing the diversity and frequency of participation in social activities. The constant adjustment of China's fertility policy increases the possibility of the elderly caring for multiple grandchildren, and prolongs their time of caring for grandchildren. The elderly caring for grandchildren is a proactive choice, which continuously relieves the child-rearing stress, and highlights the family value and social value of the elderly. At the same time, raising and accompanying grandchildren makes the elderly's lives more fulfilling and positive, which in turn promotes participation in social activities, and the mental health of the elderly.