Grandparent

Grandparents, individually known as grandmother and grandfather, or Grandma and Grandpa, 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, sixty-four genetic great-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 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., financial obstacles, marriage problems, illness or death), 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 to their grandchildren 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, granddad, grandmother, nan, maw-maw, paw-paw (and others which families make up themselves).

When used as a noun (e.g., "... a grandparent walked by"), grandfather and grandmother are usually used, although forms such as grandma/grandpa, granny/granddaddy or even nan/pop are sometimes used. When preceded by "my ..." (e.g., "... my grandpa walked by"), all forms are common (anywhere from "... my grandfather ..." to "... my Gramps ..."). All forms can be used in plural, but Gramps (plural Gramps) is rare.

In writing, Grandfather and Grandmother are most common, but very rare as a form of address. In speech, Grandpa and Grandma are commonly used in the United States, Canada, and Australia. In Britain, Ireland, United States, Australia, New Zealand and, particularly prevalent in the Canadian province of Newfoundland and Labrador and English-speaking Quebecers, Nan, Nana, Nanna, Nanny, Gran and Granny and other variations are often used for grandmother in both writing and speech.

In Bangladesh, Pakistan, and many parts of India, maternal grandparents are called Nana and Nani. Similarly, paternal grandparents are called Dada and Dadi. One's parents' maternal grandparents are called Par-nani and Par-nana. On similar lines, parents' paternal grandparents are called Par-dadi and Par-dada.

Numerous other variants exist, such as Granny, for grandmother. Gogo may be used for either.

Given that people may have two living sets of grandparents, some confusion arises from calling two people "grandma" or "grandpa", so often two of the other terms listed above are used for one set of grandparents. Another common solution is to call grandparents by their first names ("Grandpa George", "Grandma Anne", etc.) or by their family names ("Grandpa Jones", "Grandma Smith"). In North America, many families call one set of grandparents by their ethnic names (e.g., Hispanic grandparents might be called abuelo and abuela or "abuelito" and "abuelita", French grandparents might be called papi and mamie, Italian grandparents might be called nonno and nonna, or Dutch and German grandparents might be called Opa and Oma. In Flanders pepee or petje and memee or metje are most used). In Friesland, a common pair is pake and beppe. Northern Chinese people often use laolao and laoye, while Mandarin-speaking Southerners often use wài pó (外婆, mother's mother) and wài gōng (外公, mother's father), to refer to maternal grandparents; paternal grandparents usually are called nǎi nai (奶奶, father's mother) and yé yé (爷爷, father's father). In the Philippines, grandparents are called lolo (grandfather) and lola (grandmother).