Genealogy had at first served a purely serious purpose in determining the legal rights of related individuals to land and goods.

The game was played between three teams of two related individuals, such as a parent and child, spouses, siblings, or best friends.

Evolutionary scientists have developed a model to explain reciprocal altruism among closely related individuals.

Second, close relatives must resemble each other with respect to such a character more than do distantly related individuals.

Inbreeding - In a small population, related individuals are more likely to breed together.

Rather, it most likely runs in families because related individuals tend to have the same skin type.

Coalitions can also provide a reproductive benefit without comprising related individuals.

Inclusive fitness is suggested as the driving force behind first order alliances of related individuals.

Bands and tribes consist of small number of related individuals.

This will result in population gene frequency variation over successive generations, based on the interactions between related individuals.