This is for my grandparent Oreste. Everything started in May 1907.

Grandparents are the parents of a person’s father or mother – paternal or maternal. Every sexually-reproducing living organism who is not a genetic chimera has a maximum of four genetic grandparents, eight genetic great-grandparents, sixteen genetic great-great-grandparents, thirty-two genetic great-great-great-grandparents, etc. In the history of modern humanity, around 30,000 years ago, the number of modern humans who lived to be a grandparent increased.[citation needed] It is not known for certain what spurred this increase in longevity but largely results in the improved medical technology and living standard, but it is generally believed that a key consequence of three generations being alive together was the preservation of information which could otherwise have been lost; an example of this important information might have been where to find water in times of drought.

In cases where parents are unwilling or unable to provide adequate care for their children (e.g., death of the parents, financial obstacles, marriage problems), grandparents often take on the role of primary caregivers. Even when this is not the case, and particularly in traditional cultures, grandparents often have a direct and clear role in relation to the raising, care and nurture of children. Grandparents are second-degree relatives and share 25% genetic overlap.

A step-grandparent can be the step-parent of the parent or the step-parent’s parent or the step-parent’s step-parent (though technically this might be called a step-step-grandparent). The various words for grandparents at times may also be used to refer to any elderly person, especially the terms gramps, granny, grandfather, grandmother, nan, maw-maw, paw-paw and others which families make up themselves.

Grandparents are changing their roles in contemporary world, especially they are becoming increasingly involved in childcare. Since 2007, approximately one-third of children in the U.S. live in a household consisting of both parents and a grandparent. Around 67% of these households are also maintained by either two grandparents, or a grandmother. Likewise, more than 40% of grandparents across 11 European countries care for their grandchildren in the absence of the parents. In Britain, around 63% of grandparents care for their grandchildren who are under 16 years old. Grandparent involvement is also common in Eastern societies. For instance, 48% of grandparents in Hong Kong reported that they are taking care of their grandchildren. In China, around 58% of Chinese grandparents who are aged 45 or older are involved in childcare. In Singapore, 40% of children from birth to three years old are cared by their grandparents and this percentage is still increasing. In South Korea, 53% of children under the age of 6 years old are cared by their grandparents. Therefore, grandparents taking care of their grandchildren has become a prevalent phenomenon around the world.

There are a few reasons why grandparent involvement is becoming more prevalent. First, life expectancy has increased while fertility rates have decreased. This means that more children are growing up while their grandparents are still alive, whom can become involved in childcare. In addition, the reduced fertility rates mean that grandparents can devote more attention and resources to their only grandchildren. Second, more mothers are involved in the workforce, and thus, other caregivers need to be present to care for the child. For instance, in Hong Kong, 55% of grandparents reported that they took care of their grandchild because his or her parents have to work. In South Korea, 53% of working mother reported that they once received child care services from their parents. Third, the increasing number of single-parent families creates a need for grandparental support.

The degree of grandparent involvement also varies depending on the societal context, such as the social welfare policies. For example, in European countries such as Sweden and Denmark, where formal childcare is widely available, grandparents provide less intensive childcare. By contrast, in European countries such as Spain and Italy, where formal childcare is limited, and welfare payment is low, grandparents provide more intensive childcare. In Singapore, the grandparent caregiver tax relief was established in 2004, which enables working parents (Singapore citizens with children age 12 and below) whose children are being cared for by unemployed grandparents to receive income tax relief of 3,000 Singaporean dollars.