To what extent can human cooperative and social behaviour be explain by the selfish gene theory?

by pixiegreatorex (student)

To what extent can human co-operative and social behaviour be explained by selfish gene theory?

This essay will try to ascertain how far the selfish gene theory can explain the more ambiguous aspects of cooperative and social behaviours when these might appears to contravene the key components of the selfish gene theory (SGT from here in) as posed by Dawkins (1976); in its earliest form this is the theory that organisms are merely acting as hosts for genetic information. Under the umbrella of this theory, the organisms’ only concern is to ensure that the genetic information it hosts survives and is replicated. Therefore the motivation of the actor during any social and cooperative action is the attainment of direct or indirect genetic fitness benefits (West et al, 2007). Direct fitness benefits would be the improved reproductive success and enhanced chances of survival for the actor’s genes directly by the action taken, whereas indirect fitness benefits would be the increased chances of the continuation of the actor’s genetic material through the enhanced reproductive success and increased chances of survival of those who share the genes of the actor (Hamilton, 1975). Therefore, if a person’s individual fitness, that is their capacity to directly replicate their genes, is outweighed by their inclusive fitness, that is the degree to which a person is able to not only replicate their genes directly but the number of replications of its genes bought about by supporting others who may carry it, then according to this theory this would be favoured as it improves the persons overall genetic success regardless of how many genes they do or do not share (Heylighen, 1992).

Sachs et al (2004) define human cooperative behaviour as an interaction which involves more than one person where costs and benefits may be incurred by either both or one member in the exchange. Cooperative behaviour may benefit both parties where the benefit from the actions of both exceeds the cost of performing that action which makes the cooperation one of mutual gain, this is known as mutualism (Griffin, Gardner & West, 2006; Gardner & West, 2004). In this type of interaction the genes of both organisms would have an increased chance of survival and therefore from the perspective of the selfish gene theory the fact that both parties are receiving mutual benefits from their actions provides an obvious explanation for their participation. What really enriches this area of theory is any attempt to justify from the perspective of the SGT why some acts of social and cooperative behaviour seem to be sustained when they only appear to profit the recipient member of the exchange.

For the purpose of this essay the recipients of social and cooperative behaviours will be split in to two categories; related and non-related. The SGT appears to explain the underlying motivations for helping these people in different ways so this will ensure that any strengths or limitations of the theory are outlined where they are specifically relevant.

The debate seems to be less paradoxical when regarding interactions between those who potentially share the same genes. From the perspective of the selfish gene theory a seemingly adequate explanation is provided for this type of discrimination; kin selection (Maynard-Smith, 1964) and mechanisms through which this discrimination is maintained; the application of Hamilton’s rule, limited dispersal and the greenbeard effect (Hamilton, 1964, 1975; Dawkins, 1976; Jansen & Van Baalen, 2006).

Hamilton (1964) supported Dawkins and the genes eye view of evolution; according to Hamilton’s rule (1964) b>c/r whereby ‘b’ is the benefit to the recipient by the actors behaviour, ‘c’ is the cost ensued by the actor by the action taken and ‘r’ is the degree to which the actor and recipient are related, it stands to reason that as long as the cost ensued by the actor is offset by the overall benefit to the potentially shared genes in terms of reproductive possibility that natural selection will increase the presence of the gene in question. It stands to reason therefore that parents will protect their children selflessly because, in overly simplified terms, their offspring carries half of their genes. Brothers and sisters carry half of the same genes and this explains why they might behave altruistically towards each other. However, parental behaviour is far more altruistic and this is explained by this theory in terms of life expectancy; the greater the life expectancy, the greater the chance of the genes being replicated. However, it is difficult to understand why a person may behave altruistically towards grandparents and other elderly members of the family when often this doesn’t appear to benefit the actor’s genetic success directly or indirectly; the fact that this seems to decrease the fitness of the actor means that this provides a limitation regarding the kin selection concept within the selfish gene theory when trying to explain cooperative and social behaviours.

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Another challenge to the kin selection theory is the questionable ability of the actor to be able to distinguish someone with whom they are related from someone with whom they are not. Dawkins (1976) explains a person’s capacity to discriminate outside of direct kin through a phenomenon known as the Green beard effect (Hamilton, 1964, 1975; Dawkins, 1976; Jansen & Van Baalen, 2006). According to Dawkins (1976) genes help to program those they embody to behave in ways that ensure their survival and replication; this genetically influenced behaviour is known as phenotypic (Johannsen, 1911). Dawkins posits that the closer organisms are related the more genes they will share and where the phenotypic propensity is to behave altruistically, these organisms will behave in this way towards each other to protect the interest of those genes. This apparent altruistic behaviour is therefore selfish at the level of the genes even if it appears to be altruistic at the level of the organism and so kin discrimination is an ultimately selfish mechanism to ensure copies of these shared genes are populated in greater numbers.

Another way of ensuring that the actor bestows these generosities on those who share their genes is the assumption that the recipients live near to the actor which is known as limited dispersal. This is the theory that a person is more likely to help another person from a neighbouring group due to an increased likelihood that they might share genes based upon the proximity and the likelihood that the degree of relatedness will therefore be above average for the population (Hamilton, 1964). More recent research demonstrates that the potential benefits from cooperation through higher probabilities of relatedness are cancelled out by the competition led to by this relatedness (Kummerli et al, 2008) and that cooperation is more likely to be favoured when those who share a higher degree of relatedness disperse in groups, this is known as budding dispersal (Kummerli et al, 2008). This may mean that dispersal does have a benefit on the selection of cooperative traits at the genetic level but only if the organisms disperse in groups; SGT would likely suggest that genes therefore influence people to disperse in groups to reap these fitness benefits.

Whilst this discrimination towards helping those who share the same genes makes sense, based on this logic is it incapable of explaining why cooperative and social behaviours occur between those who do not share genes. Why would a person behave in a way that seemingly has no fitness benefits for themselves or those of possible genetic significance and furthermore what if this behaviour appears to bestow cost on the actor.

An explanation for why people help others when they are not related to the recipient is ‘reciprocal altruism’ (Trivers 1971; Kreb & Davies, 1993; Griffin & West, 2002; Frank, 2003; West et al, 2006; Lehmann & Keller, 2006) this is where people help each other on the assumed proviso that when they need help another person will return this type of behaviour (Frank, 2003; West et al, 2006). SGT would stress that through this interaction there is a direct long term fitness benefit for the actor. However, without concrete reciprocal altruism where by favours are paid directly in proportion to the original favour in exactly equal measures, there is no certainty that the favour will ever be returned and therefore this concept may be found wanting; this will be demonstrated later when the public goods game is explained outlining the ways in which this type of behaviour decreases over time. Perhaps these social and cooperative behaviours are better understood when they are examined in their context; the impact of a behaviour on individual fitness relative to the group to which the individual belongs.

There is evidence that some people have a strong predisposition to act in a way that rewards cooperative behaviour and punishes those who violate this norm and they do so in a way which incurs significant cost to themselves with seemingly no expectation of reciprocation by any other party at any date in the future, altruistically. This behaviour is indiscriminate and thus attempts to explain cooperative and social behaviours directed outside of those related to the actor; this propensity is known as strong reciprocity and there is experimental evidence to support its existence. Drawing again on game theory, the ‘public goods’ game is an experimental means to measure cooperation between people who have never met in a situation where there are repeated interactions with outcomes that either benefit the group as a whole or the individual. Each individual starts the game with the same number of points; these points are swapped at the end of the game for real money. The players are told that there will be a set number of rounds, 10 for example and that in each round they can contribute a certain percentage of their points in to a common account and the rest in to their own personal account. At the end of each round the experimenters would tell the players the total amount in the common account and would pay a percentage of this in to the personal accounts of all the players. Therefore, if people acted purely in their self-interest as relayed in the often misunderstood purest form of the selfish gene theory, this person would not contribute to the common account in the first place and would reap the rewards of everyone else’s contribution. Contributions to the common fund started at approximately 50% of the total points of each player but this decreased over the course of the game as some people put less in the common account. Justifications for the decline in cooperation were that the only way to punish people who were not contributing to the common account was to decline to contribute to that account also. It begs the question as to how sustainable cooperative and social behaviours are without a significant deterrent to behaving selfishly. When this game was conducted with opportunity to heavily punish non contributors by using their own points to deduct from those of the non-contributing players this was consistently selected. This pattern of behaviour meant that cooperation no longer decreased over the rounds so cooperative behaviour was maintained by reward and punishment as it often is in society. More recent neurobiological evidence supports the notion that even this seemingly altruistic behaviour by the actor is selfish at a genetic level, De Quervain et al (2004) found that when a person punishes another for non-cooperative behaviour the dorsal striatum is stimulated and as this is the circuitry involved in reward-related activity there is a direct fitness benefit being bestowed by this behaviour to the actor. Additionally, there are indirect benefits for the group to which the actor belongs as this behaviour increases their survival chances and productivity. Therefore the overall fitness benefits to the person’s genes through the ultimate maintenance of the group and societal norms which help to preserve that group outweighs the personal sacrifices made to maintain this system of cooperative and social fairness which has fitness benefits for those who engage in it (Hamilton, 1964, 1975). If selfish behaviour increases a persons’ overall fitness then it would seem obvious that genes which promote selfishness should increase their presence in the gene pool and that altruistic genes would therefore be outbred. This would mean that Dawkins (1976) explanation for cooperative and social behaviour would be fundamentally flawed. However, game theory has shown how important the combination of those who behave selfishly and those who behave in a seemingly altruistic way is to the evolution of the genes that promote these behaviours. A game called ‘prisoners dilemma’ demonstrates that when two people behave altruistically they increase the overall fitness of both parties and hence the gene that promotes this behaviour is likely to survive and be replicated. When both parties behave selfishly both decrease their overall fitness which makes the gene responsible less likely to survive and be replicated and when one partner behaves selfishly it is their own fitness that will increase but if there is discrimination from those who have the altruistic genes in their willingness to interact with those carrying the selfish gene then this explains why the population is not overcome by those carrying the selfish gene.

Dawkins purports that consciousness has evolved to be able to override the influence of the genes and that the more executive decisions are made at the helm of this consciousness. It is the relationship between the genes and consciousness that determine how a person will behave and the influence of the environment and its culture shapes consciousness more than genes do. Dawkins acknowledged a meme as a unit of culture that can be passed from person to person at a much faster rate than genes would be and therefore memes create rules for cooperative and social behaviour and these rules help to maintain systems of cooperation by punishing those who do not engage fairly in social interactions. Therefore where behaviours cannot be explained by genes they are explained by memes and Cartesian-dualism.

Because ultimately genes are primarily concerned with their own replication, they influence people to behave in ways that are most likely to meet this need; altruistic and cooperative behaviour has evolved as a consequence of its success at replicating itself and therefore cooperative and social behaviour is explained by the SGT as having evolved at the level of the genes through selfish means. Cooperative and social behaviour at the level of the organism is therefore only a mechanism to ensure that the needs of the genes are being met. The survival of the fittest is therefore not a competition for resources and advantageous selfish behaviour but it is an enhanced chance of survival and reproduction bestowed on those who behave in efficient ways such as through cooperative and social behaviours (Margulis & Lovelock, 1974)

Conclusively, Dawkins SGT appears to be able to offer adequate explanations for cooperative and social behaviours that enhance the fitness of the actor and those who share the same genes. If the fitness is not directly or indirectly enhanced with an immediate effect then this can be explained as having a lifetime fitness benefit by this same theory but it is worth noting that measuring lifetime fitness benefits is difficult to do which limits this explanation. The weaker the genetic connection between the actor and the recipient the weaker the theory becomes when offering explanations for cooperative and social behaviours, especially as the behaviour of the actor becomes increasingly altruistic. Therefore from the perspective of the SGT even apparently cooperative and social behaviour at the level of the organism is always one of selfish motivation at the level of the genes; put succinctly, ‘scratch an altruist and watch a hypocrite bleed’ (Ghiselin, 1974).

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