Sunday, April 10, 2011

Days of "Altruism"

Last week India was upbeat with Anna Hazare’s social cause. It can be be classically defined as truly altruistic endeavour. But, was it altruism? What is altruism? In a pure sense, it is the selfless concern for welfare of others. It is a traditional virtue in many cultures. There is no expectation of reward. Is pure altruism possible, though? Social evolution is a discipline that is concerned with social behaviours, i.e. that have fitness consequences for individuals other than the actor, does classify altruism as one of the accepted social behaviours. Social behaviours have been categorized by W D Hamilton in 1960s as follows:

  1. Mutually beneficial - a behavior that increases the direct fitness of both the actor and the recipient
  2. Selfish - a behavior that increases the direct fitness of the actor, but the recipient suffers a loss
  3. Altruistic - a behavior that increases the direct fitness of the recipient, but the actor suffers a loss
  4. Spiteful - a behavior that decreases the direct fitness of both the actor and the recipient

Hamilton proposed the above classification saying that Darwin’s natural selection favoured mutually beneficial or selfish behaviours while kin selection could explain altruism and spite. The closed we come to understanding altruism scientifically is by understanding biological altruism. In evolutionary biology, an organism is said to behave altruistically when its behaviour benefits other organisms, at a cost to itself. The costs and benefits are measured in terms of reproductive fitness, or expected number of offspring. So by behaving altruistically, an organism reduces the number of offspring it is likely to produce itself, but boosts the number that other organisms are likely to produce. This biological notion of altruism is not identical to the everyday concept. In everyday parlance, an action would only be called ‘altruistic’ if it was done with the conscious intention of helping another. But in the biological sense there is no such requirement. Indeed, some of the most interesting examples of biological altruism are found among creatures that are (presumably) not capable of conscious thought at all, e.g. insects. For the biologist, it is the consequences of an action for reproductive fitness that determine whether the action counts as altruistic, not the intentions, if any, with which the action is performed.

For decades, selflessness - as exhibited in eusocial (true social) insect colonies where workers sacrifice themselves for the greater good – has been explained in terms of genetic relatedness. Called kin selection, it was a neat solution to the conundrum of selflessness. The dominant evolutionary theory and its influence on human altruism are now under attack.

On the face of it, self-serving humans are nothing like paper wasps, which along with their relatives, ants, bees and termites, are defined as eusocial, creatures that display the highest levels of social organization. Famed Harvard biologist and author Edward O. Wilson, who gave eusociality its first clear meaning, refers to such behaviour as “civilization by instinct”.

The evolutionary theories , in particular kin selection, go a long way towards reconciling the existence of altruism in nature with Darwinian principles. However, some people have felt these theories in a way devalue altruism, and that the behaviours they explain are not ‘really’ altruistic. The grounds for this view are easy to see. Ordinarily we think of altruistic actions as disinterested, done with the interests of the recipient, rather than our own interests, in mind. But kin selection theory explains altruistic behaviour as a clever strategy devised by selfish genes as a way of increasing their representation in the gene-pool, at the expense of other genes. Surely this means that the behaviours in question are only ‘apparently’ altruistic, for they are ultimately the result of genic self-interest? Reciprocal altruism theory also seems to ‘take the altruism out of altruism’. Behaving nicely to someone in order to procure return benefits from them in the future seems in a way the antithesis of ‘real’ altruism — it is just delayed self-interest.

To some extent, the idea that kin-directed altruism is not ‘real’ altruism has been fostered by the use of the ‘selfish gene’ terminology of Dawkins (1976). As we have seen, the gene's-eye perspective is heuristically useful for understanding the evolution of altruistic behaviours, especially those that evolve by kin selection. But talking about ‘selfish’ genes trying to increase their representation in the gene-pool is of course just a metaphor (as Dawkins fully admits); there is no literal sense in which genes ‘try’ to do anything. Any evolutionary explanation of how a phenotypic trait evolves must ultimately show that the trait leads to an increase in frequency of the genes that code for it (presuming the trait is transmitted genetically.) Therefore, a ‘selfish gene’ story can by definition be told about any trait, including a behavioural trait, that evolves by Darwinian natural selection. To say that kin selection interprets altruistic behaviour as a strategy designed by ‘selfish’ genes to aid their propagation is not wrong; but it is just another way of saying that a Darwinian explanation for the evolution of altruism has been found. As Sober and Wilson (1998) note, if one insists on saying that behaviours which evolve by kin selection / donor-recipient correlation are ‘really selfish’, one ends up reserving the word ‘altruistic’ for behaviours which cannot evolve by natural selection at all.

For the past four decades kin selection theory has been the major theoretical attempt to explain the evolution of eusociality,” writes Wilson and Harvard theoretical biologists Martin Nowak and Corina Tarnita in an Aug. 25 Nature 2010 paper. “Here we show the limitations of its approach.”

According to the standard metric of reproductive fitness, insects that altruistically contribute to their community’s welfare but don’t themselves reproduce score a zero. They shouldn’t exist, except as aberrations — but they’re common, and their colonies are fabulously successful. Just 2 percent of insects are eusocial, but they account for two-thirds of all insect biomass.

Kin selection made sense of this by targeting evolution at shared genes, and portraying individuals and groups as mere vessels for those genes. Before long, kin selection was a cornerstone of evolutionary biology. It was invoked to help explain social and cooperative behavior across the animal kingdom, even in humans.

But according to Wilson, Nowak and Tarnita, the great limitation of kin selection is that it simply doesn’t fit the data. Wilson et al claim that looking at a worker ant and asking why it is altruistic is the wrong level of analysis. The important unit is the colony.

Their new theory of eusocialty may be useful in understanding, for example, how single-celled organisms gave rise to multi-celled organisms. Human selflessness and cooperation, involves interation of culture and sentience, not just genes and genetics. As claimed in the paper, ‘there are certain things we can learn from ants. Its easier to think about ants, but people are complicated’.

I am not proposing any scientific evidence for human altruism, indeed if it exists. Most definitely not for the last week’s event that drew me to read more about it. Was it pure altruism, or apparent altruism? Or kin selection? Or plain selfishness?

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