What is it about?
Darwin’s theory of evolution predicts intense competition to survive and successfully raise young i.e. transfer one’s genes into future generations. Genes are what survive over evolutionary time and so it seems that the one trait that genes will be selected to display most clearly is selfishness – hence the term the ‘selfish gene’. Nevertheless altruistic and cooperative behaviour appears to reduce the ability to transfer one’s genes into future generations and yet has been observed widely in nature and particularly in humans. Explaining why and how such behaviour exists is recognized to be one of the most important puzzles facing modern biology. Currently, many biologists believe that this puzzle can be explained by reciprocity. It is argued that an exchange of altruistic acts between individuals over time (‘you scratch my back, I’ll scratch yours’) increases their ability to transfer altruistic genes into future generations. Others, however, argue that it would be too easy to cheat in reciprocal relationships and that competition would thus quickly break reciprocity down. In this article I review studies conducted with colleagues in which we examine alternatives to reciprocity theory in humans. These alternatives are based on the likely indirect consequences of the development of the human brain. Firstly, we argue that the expansion of the human brain would have made raising children far more costly and difficult for our ancestors. In order to successfully transfer your genes into future generations, it follows that finding a mate with high quality parental resources and skills would have been very important. But these qualities are not easy to detect in a potential mate. Instead, we propose that displays of altruistic and cooperative behaviour (e.g. bravery in defence of one’s group from outside attack, caring for an elderly person) would have provided an accurate guide as to whether a potential mate had the ability and willingness to make a good parent. Secondly, the developing human brain led to our ancestors inventing sophisticated weaponry that were used to hunt game and enjoy a protein-rich diet. But these weapons might well also have been used to inflict death and serious injury much more easily and speedily in disputes. In such an environment, ‘selfish’ individuals are likely to have become involved far more often in lethal disputes in which weapons were used and death and serious injury resulted. We conclude that, in both hypothesized evolutionary environments, genes associated with ‘selfish’ genes are likely to have been penalized and those related to altruism and cooperation favoured. As a result, modern humans have the potential to behave altruistically and cooperatively in a way that other species do not because of these unique selection processes.
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Why is it important?
This article summarizes two alternatives to reciprocity theory in explaining how and why human altruism and cooperation evolved. It also provides a deeper, more philosophical insight into human behaviour (see below).
Perspectives
Reciprocity theory assumes that altruistic and cooperative behaviour is really a disguised form of selfishness in that it may be the best way of competing with others i.e. surviving and transferring one’s genes into future generations. The two hypothesized environments discussed in this article also see this behaviour as a disguised form of selfishness on the same grounds. The difference between these two theories, however, is that, with the latter, the hypothesized environments no longer exist in the modern world. The human brain has stopped expanding while, in the modern world, we have developed legal systems that suppress unauthorized use of weapons. But the altruistic and cooperative genes that served us well in these past environments continue to be expressed in the modern world where they might now actually reduce our ability to compete. Modern humans can therefore be seen as having the potential to display genuinely altruistic and cooperative behaviour. Nevertheless there is no reason to believe that the ‘selfish gene’ is anything other than a powerful motivator in human behaviour. But we might also have the potential to act altruistically and cooperatively! In this article it is suggested that genes which express these conflicting emotions in human behaviour might give us the potential to exercise free will. Thus a biological explanation may be capable of resolving a long-standing philosophical problem i.e. are humans capable of exercising genuine free will?
Tim Phillips
Read the Original
This page is a summary of: Human Altruism and Cooperation Explainable as Adaptations to Past Environments No Longer Fully Evident in the Modern World, The Quarterly Review of Biology, September 2015, University of Chicago Press,
DOI: 10.1086/682589.
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