Competitive altruism
Encyclopedia
Competitive altruism is a possible mechanism for the persistence of cooperative behaviors
, specifically those that are performed unconditionally. The theory of reciprocal altruism
can be used to explain behaviors that are performed by a donor who receives some sort of benefit in the future. When no such compensation is received, however, reciprocity
fails to explain altruistic behavior
.
To explain competitive altruism, Roberts uses the example of preening among birds. Because certain birds cannot reach parasites on all parts of their bodies, particularly their necks, they benefit from preening one another. For any given bird, there is an entire flock
of potential preeners, who compete in hopes of establishing a beneficial relationship. Cheaters, or those birds that try to be preened without preening others, do not compete and thus are excluded from these relationships. Their fitness
is lowered because they are ostracized by members of the flock.
McNamara et al. quantitatively analyzed this theory. Like Robert Axelrod
, they created a computer program
to simulate repeated interactions among individuals. The program involved players with two genetically determined traits
, a ‘cooperative trait’ and a ‘choosiness trait.’ They found the following results:
The development of such cooperation requires variation in the degree of cooperation and choosiness, which the researchers attributed to genetic mutation
and variation
. McNamara et al. also determined that since a period of searching is required for ‘mutually acceptable’ players to find one another, competitive altruism is more likely to arise in animals with long life spans.
, an individual may benefit the most in an one-time interaction with another by defecting (i.e. receiving benefits without incurring any cost to itself). However, in an iterated prisoner's dilemma, where individuals interact more than once, if the act of defecting makes the individual less likely to attract a fit
mate in the future, then cooperative behavior will be selected for.
This selection for cooperation is even stronger if an individual's action in an interaction is observed by third-party individuals, for the possibility of forming a reputation
arises. Amotz Zahavi
, famous for his work with the altruistic Arabian babbler
, suggests that this level of "social prestige" will affect which individuals interact with one another and how they behave.
Competitive altruism has been demonstrated repeatedly in studies with humans. For instance, individuals are more generous when their behaviour is visible to others and altruistic individuals receive more social status and are selectively preferred as collaboration partners and group leaders... Adding insights from sexual selection theory research has also found that men behave more altruistically in the presence of an (attractive) female and altruistic males are selectively preferred as long-term sexual partners.
. With competitive altruism, cooperation is considered a trait that provides a signaling
benefit, and thus is subject to sexual selection
. Like a peacock's tail, cooperation persists and is magnified, even though it carries a cost to the individual. Cooperation must be significantly costly to the individual, such that only a limited proportion of the population is fit enough to partake.
Roberts builds on the idea of altruism as a signaling benefit with his "free gift theory". Because the recipient gains some benefit from the interaction with the donor, there is an incentive to pay attention to the signal. For example, some male birds will offer food to a potential mate. Such behavior, called courtship
feeding, not only benefits the female, who receives a meal without expending any energy, but also conveys the ability of the male to forage. Consequently, the signal is kept true (i.e. it remains a correct reflection on the fitness of the mate).
However, the connection between competitive altruism and signaling is not without criticism. Wright raises the point that an altruistic signaling behavior like gift giving would cause a "flow of fitness from the higher quality individual to the lower quality one" and reduce the veracity of the signal. To account for this likely trend, Wright stipulates that the altruistic behavior must be directed at a mate or ally. In order for the theory to hold true, the signaling benefit would have to be shown to improve the individual's fitness beyond the benefit gained from the "investment" in the partner.
Cooperation
Cooperation or co-operation is the process of working or acting together. In its simplest form it involves things working in harmony, side by side, while in its more complicated forms, it can involve something as complex as the inner workings of a human being or even the social patterns of a...
, specifically those that are performed unconditionally. The theory of reciprocal altruism
Reciprocal altruism
In evolutionary biology, reciprocal altruism is a behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar manner at a later time...
can be used to explain behaviors that are performed by a donor who receives some sort of benefit in the future. When no such compensation is received, however, reciprocity
Reciprocity
Reciprocity may refer to:*Reciprocity , used to describe the concept of free trade with the United States of America** Reciprocal trade agreement, entered into in order to reduce tariffs, quotas and other trade restrictions on items traded between the signatories*Reciprocity , the relationship...
fails to explain altruistic behavior
Altruism
Altruism is a concern for the welfare of others. It is a traditional virtue in many cultures, and a core aspect of various religious traditions, though the concept of 'others' toward whom concern should be directed can vary among cultures and religions. Altruism is the opposite of...
.
To explain competitive altruism, Roberts uses the example of preening among birds. Because certain birds cannot reach parasites on all parts of their bodies, particularly their necks, they benefit from preening one another. For any given bird, there is an entire flock
Flock (birds)
A flock is a group of birds conducting flocking behavior in flight, or while foraging. The term is akin to the herd amongst mammals. The benefits of aggregating in flocks are varied and flocks will form explicitly for specific purposes...
of potential preeners, who compete in hopes of establishing a beneficial relationship. Cheaters, or those birds that try to be preened without preening others, do not compete and thus are excluded from these relationships. Their fitness
Fitness (biology)
Fitness is a central idea in evolutionary theory. It can be defined either with respect to a genotype or to a phenotype in a given environment...
is lowered because they are ostracized by members of the flock.
McNamara et al. quantitatively analyzed this theory. Like Robert Axelrod
Robert Axelrod
Robert M. Axelrod is an American political scientist. He is Professor of Political Science and Public Policy at the University of Michigan where he has been since 1974. He is best known for his interdisciplinary work on the evolution of cooperation, which has been cited in numerous articles...
, they created a computer program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
to simulate repeated interactions among individuals. The program involved players with two genetically determined traits
Trait (biology)
A trait is a distinct variant of a phenotypic character of an organism that may be inherited, environmentally determined or be a combination of the two...
, a ‘cooperative trait’ and a ‘choosiness trait.’ They found the following results:
‘Paradoxical’ trait combinations yield particularly low payoffs: individuals with low choosiness but high effort tend to get exploited by their co-players; individuals with high choosiness but low effort waste their time searching for better co-players, which are, however, unlikely to accept them. The positive correlation between choosiness and cooperativeness leads to a positive assortment between cooperative types – an essential feature of all mechanisms that promote cooperation.
The development of such cooperation requires variation in the degree of cooperation and choosiness, which the researchers attributed to genetic mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
and variation
Genetic diversity
Genetic diversity, the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary....
. McNamara et al. also determined that since a period of searching is required for ‘mutually acceptable’ players to find one another, competitive altruism is more likely to arise in animals with long life spans.
The prisoner's dilemma
To relate this condition to the prisoner's dilemmaPrisoner's dilemma
The prisoner’s dilemma is a canonical example of a game, analyzed in game theory that shows why two individuals might not cooperate, even if it appears that it is in their best interest to do so. It was originally framed by Merrill Flood and Melvin Dresher working at RAND in 1950. Albert W...
, an individual may benefit the most in an one-time interaction with another by defecting (i.e. receiving benefits without incurring any cost to itself). However, in an iterated prisoner's dilemma, where individuals interact more than once, if the act of defecting makes the individual less likely to attract a fit
Fitness (biology)
Fitness is a central idea in evolutionary theory. It can be defined either with respect to a genotype or to a phenotype in a given environment...
mate in the future, then cooperative behavior will be selected for.
This selection for cooperation is even stronger if an individual's action in an interaction is observed by third-party individuals, for the possibility of forming a reputation
Reputation
Reputation of a social entity is an opinion about that entity, typically a result of social evaluation on a set of criteria...
arises. Amotz Zahavi
Amotz Zahavi
Amotz Zahavi is an Israeli evolutionary biologist, a Professor Emeritus at the Zoology Department of Tel Aviv University, and one of the founders of the Society for the Protection of Nature in Israel...
, famous for his work with the altruistic Arabian babbler
Arabian Babbler
The Arabian Babbler is a passerine bird belonging to the genus Turdoides, a genus of Old World babblers.It is 26–29 cm long with a wingspan of 31-33.5 cm and a weight of 64-83 grams. It has a fairly long curved bill, a long tail, rounded wings and strong legs and feet. The plumage...
, suggests that this level of "social prestige" will affect which individuals interact with one another and how they behave.
Competitive altruism has been demonstrated repeatedly in studies with humans. For instance, individuals are more generous when their behaviour is visible to others and altruistic individuals receive more social status and are selectively preferred as collaboration partners and group leaders... Adding insights from sexual selection theory research has also found that men behave more altruistically in the presence of an (attractive) female and altruistic males are selectively preferred as long-term sexual partners.
The handicap principle
The theory of competitive altruism also helps one connect such behavior to the handicap principleHandicap principle
The handicap principle is a hypothesis originally proposed in 1975 by biologist Amotz Zahavi to explain how evolution may lead to "honest" or reliable signaling between animals who have an obvious motivation to bluff or deceive each other...
. With competitive altruism, cooperation is considered a trait that provides a signaling
Signalling theory
Within evolutionary biology, signalling theory is a body of theoretical work examining communication between individuals. The central question is when organisms with conflicting interests should be expected to communicate "honestly"...
benefit, and thus is subject to sexual selection
Sexual selection
Sexual selection, a concept introduced by Charles Darwin in his 1859 book On the Origin of Species, is a significant element of his theory of natural selection...
. Like a peacock's tail, cooperation persists and is magnified, even though it carries a cost to the individual. Cooperation must be significantly costly to the individual, such that only a limited proportion of the population is fit enough to partake.
Roberts builds on the idea of altruism as a signaling benefit with his "free gift theory". Because the recipient gains some benefit from the interaction with the donor, there is an incentive to pay attention to the signal. For example, some male birds will offer food to a potential mate. Such behavior, called courtship
Mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
feeding, not only benefits the female, who receives a meal without expending any energy, but also conveys the ability of the male to forage. Consequently, the signal is kept true (i.e. it remains a correct reflection on the fitness of the mate).
However, the connection between competitive altruism and signaling is not without criticism. Wright raises the point that an altruistic signaling behavior like gift giving would cause a "flow of fitness from the higher quality individual to the lower quality one" and reduce the veracity of the signal. To account for this likely trend, Wright stipulates that the altruistic behavior must be directed at a mate or ally. In order for the theory to hold true, the signaling benefit would have to be shown to improve the individual's fitness beyond the benefit gained from the "investment" in the partner.