Don't be a sucker. Be an altruist.

Is altruistic behaviour among humans advantageous just for the group or for the individual as well? Are altruists in fact the unlucky martyrs of evolution that boost the success of their groups by sacrificing their own selective fitness? This is what my friend G. suggested to me recently. As I find this point of view a very pessimistic one I decided to try and argue against it (even though arguing against G. is never an easy task :-) ). Thankfully modern evolutionary theory came to my rescue!
From a biological point of view altruism is defined as “behaviour that benefits an individual(s) while being detrimental (cost > benefit) to the actor in the short term”. A key element in the above definition is the “short term” qualifier. Let me explain this in more detail.
Any type of altruistic behaviour has behind it some form of incentive. This incentive can take many forms; expected -even if uncertain- reciprocity by the benefited or a third party, social accolades, psychological and physiological reward in the form of stimulation of pleasure centers in the brain or even the hope for restitution in an after-life,. Therefore two things should be evident. First, as opposed to biological altruism, no such thing as “true altruism” exists since there is always some selfish incentive behind any altruistic action, even if that incentive is not immediately obvious. Second it is not clear that altruistic behaviour is detrimental to the fit of an individual. Early theories that tried to reconcile the apparent oxymoron of altruism and Darwinism considered the evolutionary advantages of “altruistic genes” for a group or the kinship of carriers of such genes. However these theories have since been complemented by ideas such as those of reciprocal altruism and inclusive fitness which argue that altruistic behaviour can evolve without the need for group selection. In other words altruism could be only prima facie detrimental to an individual but in fact advantageous when possible future and indirect compensations are taken into consideration. If that line of argument is true it is only reasonable to suggest that the positive psychological and physiological responses to altruistic behaviour are there to promote selfless actions that might seem irrational in the short term but are advantageous for the group as well as the individual in the long term.
An excellent review of altruism from an evolutionary/biological point of view.