Charles Darwin was the first to discuss the concept of kin selection (without using that term). In On the Origin of … See more

Formally, genes should increase in frequency when
where
r = the genetic relatedness of the recipient to the actor, often defined as the probability that a gen… See more

Altruism occurs where the instigating individual suffers a fitness loss while the receiving individual experiences a fitness gain. The sacrifice of one individual to help another is an example.
Hamilton o… See more

Eusociality (true sociality) occurs in social systems with three characteristics: an overlap in generations between parents and their offspring, cooperative brood care, and specialised castes of non-reproductive individuals… See more

Whether or not Hamilton's rule always applies, relatedness is often important for human altruism, in that humans are inclined to behave more altruistically toward kin than toward unrelated individuals. Many people cho… See more

Though originally thought unique to the animal kingdom, evidence of kin selection has been identified in the plant kingdom.
Competition for resources between developing zygotes in plant ovaries increases … See more

The theory of kin selection has been criticised by W. J. Alonso (in 1998) and by Alonso and C. Schuck-Paim (in 2002). They argue that the behaviours which kin selection attempts to explain are not altruistic (i… See more