Altruism is said to be evolutionarily stable if it survives evolutionary selection. Instead of studying directly the evolution of behavior, which is the usual approach in evolutionary biology1 and in evolutionary game theory (see, e.g. Hammerstein and Selten, 1994), we consider rational behavior for given preferences.
What is the problem with altruism?
The first is the classic problem of altruism, defined as the issue of how a behavior which decreases an individual's lifetime reproductive success, while helping another individual (or individuals) increase their lifetime reproductive success, can evolve.
How are altruistic behaviors evolutionarily advantageous?
In evolutionary biology, an organism is said to behave altruistically when its behaviour benefits other organisms, at a cost to itself. ... 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.
