I have made the point elsewhere that it is hard to see how Darwinian evolution - the 'survival of the fittest' - can produce altruistic behaviour. Darwin himself recognised this point.
For the record...
Altruism is not the only problem area. It is hard to see how evolution can explain the existence of humour, art, singing, painting, poetry, most cookery and addiction, amongst other things. But we are talking here about altruism.
Of course, altruism is not the sort of thing you either have or you don't have. Almost everyone behaves in altruistic ways some of the time, towards some people, and some of this behaviour can be explained by evolutionary theory.
People have tried to provide an evolutionary explaination of altruism, using several different approaches.
The easy starting point is altruistic behaviour directed towards our own offspring or close relatives. They share many of our own genes, so to help them is also helping our own genes survive. And that is what it is all about.
This explains selfless ants, and some human behaviour. But it does not explain why people give to charities to help people they will never meet, or risk their lives for the sake of strangers.
Another approach is reciprocity: I risk my life for you, in the hope that you will reciprocate and risk your life for me or my children one day.
This can explain why I might invest my time and energy to help my neighbours - those with whom I don't share any close genetic ties, but who will probably be around to help me out when I need it.
But, again, this simply doesn't provide any evolutionary reason why I should help or risk my life for a stranger.
Selection between groups had been considered and discounted by evolutionists, but is now being put forward again. It is described in an article by Wilson and Wilson in the 3 November 2007 edition of New Scientist, pages 42-46.
In abstract terms, the concept clearly works. It is the solution Darwin came up with: groups containing mainly altruists have a decisive advantage over groups containing mainly selfish individuals, even if selfish individuals have an advantage over altruists within each group.
The article correctly observes that there are circumstances in which between-group selection is important. However, "Some of the best evidence comes from microbes," which should be worrying for anyone who thinks this solves the problem.
In fact, only two examples of group selection are provided.
One of them concerns lions defending their territory. This would translate directly into the human habit of warfare. I can readily see that in the context of warfare, an army of altruistic people will defeat an army in which everyone is out to save their own skin. This would explain bravery and bonding in the army, but not generosity to strangers.
The other example concerns groups of bacteria and viruses maintained under "biologically plausible migration schemes". It was found that 'prudent' virus strains were able to outcompete more 'rapacious' strains, despite their selective disadvantage. For some reason, the authors fail to spot that prudence is the precise opposite of altruism, which is what they are supposed to be explaining!
Nothing in the article explains how group selection explains the continued presence of altruism. Yes, a group consisting of mainly altruistic people will tend to succeed more than a group of mainly selfish people. But, if altruism is an evolutionary disadvantage, the altruists within every group will tend to die out and be replaced by the selfish.
It makes no difference that one of the groups will have an advantage over the other, and the occasional person migrating from one group to the other makes no difference, either. It's a disadvantage, so it will be selected against, and this will be true in every group. My genes can be passed on if I am a live member of a weak, selfish group; they cannot be passed on if I am a dead member of a strong, altruistic group.
I find it interesting that (writing in November 2007) I have not yet found in all the scientific literature any suggestion of (what appears to me to be the two most likely explanations of altruistic behaviour.
One possibility is female selection. If females prefer to mate with altruistic males, this would provide an evolutionary edge that more than compenstated for the average cost of altruistic behaviour.
Of course, this raises the obvious question - why would females prefer to mate with altruistic males? It makes sense that they would prefer to mate with males who put them and their children first, but why prefer males who put complete strangers first? But perhaps altruism is the sort of trait it is hard to control: once you start to consider other people as having value, and you start to put their needs ahead of your own, perhaps it is hard to stop with just your partner and children. In any case, this is a modification of the 'Kinship Groups' theory which ought to be considered.
However, a much stronger possibility is that altruism is a direct result of religious faith. Religious faith provides a strong evolutionary benefit, and also provides a reason why the individual might behave in altruistic ways towards strangers.
I find it astonishing that the literature does not identify this as - at the very least - an area to be explored in more detail.
The July 2012 edition of Scientific American has 'The Evolution of Cooperation' as its main cover story. The article, "Why We Help" (pages 20-25) claims that "Far from being a nagging exception to the rule of evolution, cooperation has been one of its primary architects."
We should note that cooperation is not the same as altruism. The author, Martin A Nowak, seems to move freely between these two ideas, but it seems obvious to me that evolution struggles to explain altruism, while cooperation makes perfect evolutionary sense. Perhaps he believes that explaining cooperation will lead us to a place where we can understand altruism? It is not clear.
However, the author helpfully identifies five mechanisms for the evolution of cooperation.
We have already considered this option.
There is a nice quote from JBS Haldane, which states the mathematical value of altruism very clearly: "I will jump into the river to save two brothers or eight cousins." Assuming they are full brothers, then two brothers will contain as much of my DNA as I do; as will eight cousins. Of course, I will only jump into a river to save two brothers if they are at least as good a reproductive prospect as I am, otherwise the exchange is not worth making.
Does anyone else feel that this 'explanation' of altruism is completely contradicted by their real life experience? My experience suggests that we tend to spend much more time and energy in caring for and supporting friends and work colleagues with whom we have no family ties, than we devote to the family with whom we share parts of our unique DNA.
We have already considered this option.
There is an odd contribution here: the author says that mathematical modeling by researchers, including himself, "has helped show that selection can operate at multiple levels, from individual genes to groups of related individuals to entire species."
Well, that is not exactly a revelation. And any mathematical model has to be built, so you have to build these levels into your model and and then make it examine selection at each level. If you build your model to do this, it is hardly surprising that this is what your model does. It is like making a clay model of an elephant with two heads, and then telling people that this proves it is possible to make a clay model elephant with two heads. It might say something aout your creative capability, but it says very little about the real world.
We have already considered this option. It makes clear evolutionary sense. Strangely, the author seems to have put a lot of time and energy into 'proving' it by using a computer simulation.
Even more strangely, the simulation is built on the basis of 'people' playing the 'Prisoner's Dilemma' game. He seems to be fascinated by it. Now, I don't dispute the idea that this is a neat challenge (do look it up if you are not familiar!), but as a way of modeling cooperation in the real world, it seems about as relevant as playing contract bridge as a way of teaching teamwork.
This sounds like it could be a significant additional idea which the author brings to the table.
It recognises that consistent actions can generate a reputation - and it affirms that a 'good' reputation is an evolutionary benefit. If I get a reputation for being helpful to others, then perhaps a stranger will be helpful to me in the hope that one day I will be helpful to them.
Well - maybe. But it is still hard to see the cost-benefit thing working out. I am expending costly resources in helping you be more successful (in other words, to breed more successfully), in the vague hope that at some point in the future, some unknown person might take note of this and help me. I can't help but feel that if I want to maximise my own reproductive sucess, then there must be better ways.
And this completely fails to explain why people make anonymous donations to charity.
As far as I can tell, this approach simply affirms that group selection works even when the groups are not clearly and completely distinct. For example, it works with groups of friends where you find group memberships overlap and vary in strength, as well as in tribes where everyone clearly belongs to just one tribe.
The name of this approach derives from the seemingly obvious observation that group selection will work when the groups are fuzzy, but it will not work when there are no groups and the cooperative individuals are spread evenly through the greater population.
The 'argument' is that we have observed this happening in various contexts, such as human populations and yeast cultures.
But we already know cooperation works, and we understand that in the short term, groups with cooperative members will out-perform groups with uncooperative members. The challenge is to understand why evolution does not favour selfishness within those successful groups.
It seems obvious to me that at a simple biological level, selflessness and cooperation must be an unstable factor. Groups of selfless individuals will out-perform groups of selfish individuals; but then selfish individuals within those successful groups will out-perform the selfless individuals, and you are back where you started.
This adequately explains, for me at least, the existence of selflessness at this level - where we are programmed to do things which benefit the group more than they benifit the individual.
But we are a million miles away from explaining why people are so often willing to sacrifice and die for an abstract principle (such as 'freedom' or 'justice'), or why so many of us are willing to invest our scarce resources to help complete strangers who will never be able to help us in return, and why we so often do it in secret so that we do not even benefit from the good reputation such acts could give us.