Why would altruism be common in family groups?

Altruism is common in family groups because it enhances the survival and reproductive success of related individuals, thereby promoting the continuation of shared genes. This behavior, often referred to as kin selection, encourages family members to assist one another, as helping relatives can ultimately lead to the propagation of one's own genetic lineage. Additionally, the close genetic ties within family groups create a strong incentive for individuals to engage in selfless acts, as the benefits to relatives can outweigh the costs to oneself.