their grandchildren without the presence of the grandchildren's parents in the household. This type of involvement is especially common among ethnic minority groups. For instance, approximately 50% of custodial grandparents in the USA belong to an ethnic minority group. In general, grandparents adopt the primary caregiving role for various reasons, such as when the parents have died, been imprisoned, been deployed by the military, or lost custody of their children due to neglect or abuse. Impact On grandchildren Grandparents have different functions in child development. Not only do they provide instrumental support such as picking grandchildren up from school or feeding them, but they also offer emotional support. Furthermore, grandparents protect children from being impacted by negative circumstances, such as harsh parenting, poor economic status, and single-parent families. In addition to providing support, grandparents can also help grandchildren with their schoolwork or teach them values that are integral to their society. Grandparents can have a positive or negative impact on child development. On the one hand, previous research suggests that children and adolescents who have a close relationship with their grandparents tend to have better well-being, experience fewer emotional problems, and demonstrate fewer problematic behaviours. They are also more academically engaged and are more likely to help others. On the other hand, there are also research studies indicating that grandparent involvement is associated with more hyperactivity and peer difficulties among young children. In other words, children who are cared for by their grandparents can have more interpersonal relationship problems. Also, children who are under the care of their grandparents have poorer health outcomes such as obesity, and more injuries due to low safety awareness. On grandparents Since taking care of grandchildren could be a highly demanding job that requires constant energy and time devotion, grandparental involvement in child raising could have a negative impact on grandparents’ physical and emotional health. For example, taking care of grandchildren can reduce grandparents’ own time for self-care such as missing their medical appointments. Therefore, they are likely to have a higher chance to suffer from physical health issues. In the US, compared with those who do not take care of their grandchildren, grandparents who are involved in childcare are more likely to have poor physical conditions, such as heart disease, hypertension or body pain. Besides physical health issues, grandparents are also likely to have emotional issues. To be more specific, raising young children again