Inclusive Fitness Quotes

“Hamilton's original contribution was to realize that indirect fitness effects impact upon the purpose of adaptation. The basic condition for natural selection to favor any trait is that the individuals who carry genes for this trait are, on average, fitter than those who do not. However, the adaptations that subsequently evolve are not designed for maximizing the individual's personal fitness, but rather her inclusive fitness, i.e., the sum of all the fitness effects that she has on all of her genetic relatives, each increment or decrement being weighted by the corresponding coefficient of genetic relatedness (Hamilton 1964). In other words, the adaptive agent remains the same as in the traditional Darwinian view (i.e., the individual organism), but the adaptive agenda is changed. This idea has subsequently been formalized by Grafen (2006), who has shown the mathematical connection between the dynamics of natural selection and an optimization program in whih the individual strives to maximize her inclusive fitness, for a wide class of models, including those that allow for social interaction between relatives.
Grafen A. 2006. Optimization of inclusive fitness. J Theor Biol 238: 541-563.
Hamilton WD. 1964. The genetical evolution of social behaviour I & II. J Theor Biol 7: 1-52.”
― Andy Gardner, From Groups to Individuals: Evolution and Emerging Individuality

“EVOLUTION, ALTRUISM AND GENETIC SIMILARITY THEORY by J. PHILIPPE RUSHTON

The reason people give preferential treatment to genetically similar others is both simple and profound: they thereby replicate their genes more effectively. Altruism is a very interesting phenomenon, even recognized by Darwin as an anomaly for his theory. How could it evolve through his hypothesized "survival of the fittest" individual when such behavior would appear to diminish personal fitness? If the most altruistic members of a group sacrificed themselves for others, they ran the risk of leaving fewer offspring to carry forward their genes for altruistic behavior? Hence altruism would be selected out, and indeed, selfishness would be selected in. Altruistic behaviors, however, occur in many animal species, some to the point of self-sacrifice (Wilson, 1975). For example, honey bees die when they sting in the process of protecting their nests.

Darwin proposed the competition of "tribe with tribe" to explain altruism (1871, p. 179). Thus, a tribe of people willing to cooperate and, if necessary, sacrifice themselves for the common good would be victorious over tribes made up of those less willing or able. Subsequently Herbert Spencer (1892/93) extended this, suggesting that the operation of a 'code of amity' towards the members of their own group, and a 'code of enmity' toward those of out-groups prevailed in successful groups. In non-elaborated forms, some version of "group-selection" was held by most evolutionists for several decades.

A degree of polarization followed [Wynne-Edwards' advocacy of group selection] As D. S. Wilson put it, "For the next decade, group selection rivaled Lamarkianism as the most thoroughly repudiated idea in evolutionary theory" Essentially, there did not seem to exist a mechanism by which altruistic individuals would leave more genes than individuals who cheated. The solution to this paradox is one of the triumphs that led to the new synthesis of sociobiology. Following Hamilton (1964) the answer proposed was that individuals behave so as to maximize their "inclusive fitness" rather than only their individual fitness by increasing the production of successful offspring by both themselves and their relatives, a process that has become known as kin selection. This formulation provided a conceptual breakthrough, redirecting the unit of analysis from the individual organism to his or her genes, for it is these which survive and are passed on. Some of the same genes will be found in siblings, nephews and nieces, grandchildren, cousins, etc., as well as offspring. If an animal sacrifices its life for its siblings' offspring, it ensures the survival of shared genes for, by common descent, it shares 50% of its genes with each sibling and 25% with each siblings' offspring.

…the makeup of a gene pool causally affects the probability of any particular ideology being adopted, which subsequently affects relative gene frequencies. Religious, political, and other ideological battles may become as heated as they do because they have implications for genetic fitness; genotypes will thrive more in some cultures than others. … Obviously causation is complex, and it is not intended to reduce relationships between ethnic groups to a single cause. Fellow ethnics will not always stick together, nor is conflict inevitable between groups any more than it is between genetically distinct individuals. Behavioral outcomes are always mediated by multiple causes.”
― J. Philippe Rushton

“Although a version of Hamilton's rule is indeed a fully general evolutionary truth, nothing about individual maximization can be deduced directly from this generalized form of the rule, contrary to what is sometimes implied. In particular, although the generalized Hamilton's rule yields the rb > c condition for the social trait to spread, one cannot conclude that that individuals behave as if trying to maximize the quantity (rb - c); they cannot do this, as this quantity is frequency-dependent.”
― Samir Okasha, Agents and Goals in Evolution

“THE STRATEGIC CONSEQUENCES OF CHINESE RACISM: A Strategic Asymmetry for the United States
Draft Report
Submitted 7 January 2013
Project Number: HQ006721370003000

Since our genus Homo first evolved in the Pliocene, humans have favored those who are biologically related. In general, the closer the relationship, the greater the preferential treatment. The vast majority of animals behave in this way, and humans are no different. In a world of scarce resources and many threats, the evolutionary process would select nepotism, thus promoting the survival of the next generation. However, this process is relative. Parents are more willing to provide for their own children than for the children of relatives, or rarely for those of strangers.

The essence of an inclusive fitness explanation of ethnocentrism, then, is that individuals generally should be more willing to support, privilege, and sacrifice for their own family, then their more distant kin, their ethnic group, and then others, such as a global community, in decreasing order of importance. ...

The in-group/out-group division is also important for explaining ethnocentrism and individual readiness to kill outsiders before in-group members. Irenäus Eibl-Eibesfeldt draws on psychologist Erik Erikson’s concept of “cultural pseudo speciation,” and says that in almost all cultures humans form subgroups usually based on kinship; these “eventually distinguish themselves from others by dialect and other subgroup characteristics and go on to form new cultures.” ...

When an individual considers whether to support a larger group, several metrics are available. One of these ... is ethnocentrism, a continuation of one’s willingness to sacrifice for one’s family because of the notion of common kinship. As I discussed above, the ways humans determine their relations with unrelated individuals are complex, but the key factors are physical resemblance, as well as environmental causes like shared culture, history, and language. ...

I have shown that in-group/out-group distinctions like ethnocentrism and xenophobia are not quirks of human behavior in certain settings. Instead, they are systematic and consistent behavioral strategies, or traits. They apply to all humans... They are widespread because they increased survival and reproductive success and were thus favored by natural selection over evolutionary history. ...

Chinese racism ... is a strategic asset that makes a formidable adversary. ... The government educates the people to be proud of being Han and of China. In turn, the Chinese people are proud and fiercely patriotic as well as ethnocentric, racist, and xenophobic. This aids the government and permits them to maintain high levels of popular support. ...”
― Anonymous

“The way your body looks and is shaped has never been the problem. You owe society nothing. You are allowed to focus on your health without any sort of aesthetic reasoning. Fitness has no size. We've just been conditioned to believe that it does.”
― Meg Boggs, Fitness for Every Body: Strong, Confident, and Empowered at Any Size