Evolution and Morality
Even when organisms are highly adapted to their environments, their properties do not always correspond to the intuitive notion of adaptation. … Fitness is a relative and local concept. It doesn't matter how well an organism survives and reproduces, only that it does so better than other organisms in its vicinity. As a result, many evolutionary adaptations appear selfish and shortsighted in human terms, creating problems at larger temporal and spatial scales.
If behaviors regarded as immoral in human terms are adaptive and “natural,” then aren't all the fears about evolution justified? No—because behaviors that are regarded as moral in human terms are also adaptive and “natural” under the right circumstances, which can be illustrated with the following exercise of the sort suggested by Nelson and Alters. First, the class is asked to list the behaviors that they associate with morality. The most common items include altruism, honesty, love, charity, sacrifice, loyalty, bravery, and so on. Then they are asked to list behaviors that they associate with immorality, and respond with opposite items such as selfishness, deceit, hatred, miserliness, and cowardice. With these lists in mind, the students are asked three questions: (1) What would happen if you put a single moral individual and a single immoral individual together on a desert island? (The students quickly conclude that the moral individual would become shark food within days.) (2) What would happen if you put a group of moral individuals on one island and a group of immoral individuals on another island? (The students are equally quick to conclude that the moral group would work together to escape the island or turn it into a little utopia, while the immoral group would self-destruct.) (3) What would happen if you allow one immoral individual to paddle over to Virtue Island? (The answer to this question is complex because it is a messy combination of the straightforward answers to the first two questions.)
This exercise is simple and entertaining, but profound in its implications. It shows that most of the traits associated with human morality can be biologically adaptive. Groups of moral individuals are likely to survive and reproduce better than any other kind of group. The problem with morality is its vulnerability to subversion from within. To the extent that natural selection is based on fitness differences within groups, behaviors associated with immorality are the expected outcome. To the extent that natural selection is based on fitness differences among groups, behaviors associated with morality are the expected outcome (these statements apply to all evolutionary models of cooperation and altruism when the relevant groups are appropriately defined, including inclusive fitness theory, evolutionary game theory, and multilevel selection theory). The discerning student quickly perceives a disturbing corollary: Can't behaviors that count as moral within groups be used for immoral purposes among groups? The answer to this question is “yes,” which means that moral conduct among groups is a different and more difficult evolutionary problem to solve than moral conduct within groups.
Source: David Sloan Wilson, PLoS Biology, 2005 (CC BY). Full source details.