Helping and Inclusive Fitness Benefits to Helper
Inclusive fitness is the sum of direct (personal) fitness and indirect fitness of the organism. Direct fitness is the number of offspring the individual procreates, whereas indirect fitness is defined by the number of offspring begotten by the genetic relatives of the individual. To the extent of the genetic relatedness, descendants of relatives share a proportion of copies of the individual’s genes. Thus, helping genetically related individuals, also aids the reproduction of the shared genes, providing additional (indirect) benefits for the altruist (Hamilton 1964).
Both direct and indirect fitness benefits could account for the evolution of altruism, and therefore in several cases it is difficult to separate them. Hamilton suggested a formula to define the conditions under which altruism could spread in a...
- Burnstein, E. (2005). Altruism and genetic relatedness. In D. M. Buss (Ed.), The handbook of evolutionary psychology (pp. 528–551). Hoboken: Wiley.Google Scholar
- Dawkins, R. (1982). The extended phenotype. Oxford: Freeman.Google Scholar
- Zahavi, A., & Zahavi, A. (1997). The handicap principle: A missing part of Darwin’s puzzle. Oxford: Oxford University Press.Google Scholar