Kin selection is an evolutionary theory that individuals of a species are more likely to help individuals that they are related to in order to increase the chances of a particular gene or trait being passed on to the next generation.
This form of selection has been seen as altruistic among some populations. Further studies have revealed that many times, individuals helping others of certain relatedness survive brings a benefit to that individual outside of the transfer of genes. Genetic relatedness is also determined by the heritable tendencies of an individual towards a trait expressed by another individual. This means that individuals undergoing kin selection do not necessarily share the same DNA sequence, just the heritable trait as a result of a gene or another gene that expresses a similar phenotype.
A. GARDNER1,2, S. A. WEST1 and G. WILD. The genetical theory of kin selection. Journal of Evolutionary Biology Volume 24, Issue 5, pages 1020–1043, May 2011