Individual versus Group Selection

One of the most interesting fields for understanding human behavior is evolutionary psychology (the successor to sociobiology).  Despite appearances to the contrary, this field includes both conservatives and liberals.  It continues to provoke, however, tremendous debates on both political and theoretical issues.

One of these debates involves the level at which natural selection occurs.  One way of framing this issue is whether natural selection operates only at the level of the gene or also at other levels, including the group.  People who believe that group selection occurs often describe themselves as favoring multilevel selection, since they believe selection occurs at multiple levels.  (I should note that advocates of multilevel selection might not agree with the way that this paragraph defines the debate.)

The question of whether group selection occurs has been debated over the years.  In the 1950s, there was strong support for the existence of group selection, but in the 1960s and 1970s the prevailing view swang in the opposite direction.  Animal behavior, including human behavior, could be accounted for, it was thought, entirely through kin selection and reciprocal altruism.  Under kin selection, individuals might sacrifice for their kin, but that was “selfish” because it could increase their genes (which they shared with their kin) getting into the next generation.    Under reciprocal altruism, individuals might behave “altruistically” when they were in a situation that might be repeated so that the person they helped might in the future end up helping them.  Neither of these situations was genuinely altruistic, but instead benefited the individual’s genes.

In recent years, advocates of group selection have pressed their arguments and it is my impression that this side has gained many additional adherents.  Edward Wilson, the famous author of Sociobiology, originally rejected group selection but has now converted to a view that accepts it.  Interestingly, Friedrich Hayek (who wrote about these matters in the 1970s and was, in recognizing the importance of this area for social theory, characteristically ahead of his time) was an advocate of group selection.

In the end, I am not sure with which group I agree.  Moreover, people who I greatly respect are on both sides of this issue.  In fact, it is not even clear how to properly define the terms of the debate (as the second paragraph of this post suggested.)   If, like me, you are not sure about where you stand on this issue, then one place to look is this absolutely fascinating Edge Symposium.  This is the type of thing that only really occurs on the Internet.  Steven Pinker writes the lead article, where he rejects group selection, but then there are responses written by the leading people in the field from a variety of positions.  The contributors include some of my favorite writers in this area, including: John Tooby, Richard Dawkins, David Sloan Wilson, Jonathan Haidt, Herbert Gintis, and Daniel Dennett.