Evolution and Altruism
Post of the Month: March 1997
by Richard Harter
ascha Kokott <firstname.lastname@example.org> wrote:
I have a personal question here that not only is significant to me in my endevours as a scientist (well, undergrad, well first year :-)), but as a person. All members of the same species are in competition for resources. Since this is true if a human was dying on the road we shouldn't help him/her, but let them die. This of course has great social ramifications...if we are all in fierce heartless competition how do we reconcile the need to love and be loved? Is there an answer that can reconcile both, or is love just one more illusion that religion has brought into existence?
Your question is actually a good one and is one that, posed more sharply, has been the subject of much discussion and controversy in evolutionary theory.
If you look at different species you see different ways of dealing with intra-species competition. In many species it is very much a matter of one against all - no member of the species helps any other member of the species. Indeed there are cannibalistic species in which the adults consume the young. Some species are very individualistic. Some species form flocks or herds. Some species form complex social structures. Some species have strong families; others do not. And so on and so forth.
Animal species can be rather generally divided into those which produce large numbers of offspring (r-strategy) with little investment in parental care and those which produce small numbers of offspring (k-strategy) and a high investment in parental care. We, like most vertebrates, are k-strategy animals. This implies that we invest a lot of effort in caring for and raising the young. Evolutionarily speaking, this makes sense - an animal which does not produce offspring that live and breed is a dead end, genetically speaking, no matter how well it does for itself.
So it is easy to understand why parents care for their offspring. But that is not the whole story. Why do some animals act on behalf of other members of their social group? [This is called altruism in evolutionary theory circles but it should not be confused with altruism in the human social sense.] It turns out that there are two types of "altuism", both of which make evolutionary sense. The first is called kinship altruism. My close relatives have many genes in common with me. If I act on their behalf so that they live and breed my genes will be passed on even if I don't reproduce myself. The second type is called mutual benefit altruism - I'll scratch your back if you scratch mine. Both kinds of "altruism" have obvious benefits and it is not hard to see why they are selected for.
However there is a third kind which is rarer. Some animals (principally primates) live in social groups which act together and have complex social lives within the group. In these animals group cohesion is important and there is selection for actions which preserve the integrity of the group as a whole. This type of social cooperation requires a good deal of intelligence. Our evolutionary cousins, the chimpanzees, are a good example. Chimpanzees have a complex social life. The group leader is responsible for keeping order within the group. There are friendships and alliances within a group. One group will unite against another group. There is food sharing (which may actually be tolerated food sharing) and so forth.
There is a fourth kind of group altruism which is specific to human beings. Human beings are the only animals (except possibly dolphins and whales) that have complex languages and abstract reasoning. They are the only animals that have structured cultures that endure over time. As a result humans are the only species that has - that can have - a well developed abstract moral sense. In an evolutionary sense, moral cultures are the cultures that survive. All do better if each helps the other. Cultures have laws, rules of behaviour. Those who violate the cultural norms, outlaws, are exiled in one way or another and do poorly. Those who accept the norms, the good citizens, reap the benefits of living in a successful culture.
This is not a simple matter. As we see all the time, there are conflicts between individual benefit and "doing what is right". And sometimes the decision goes one way and some times it goes another.
The upshot is that for humans our notions of right and wrong are not hard wired in our genes; they are taught to us by our culture. And although the hard rules of selection still apply their operation is very indirect. Human beings have been in the culture business for a very long time; cultures evolve but they don't evolve in the way that species evolve.
I hope this helps.
Article originally posted March 20, 1997
Article revised ("k-" and "r-" strategies reversed) on April 13, 1997
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