I’m not sure why, but group selection seems to be a topic that inspires vociferous but poorly-considered critique. An example from Steven Pinker:

Human beings live in groups, are affected by the fortunes of their groups, and sometimes make sacrifices that benefit their groups. Does this mean that the human brain has been shaped by natural selection to promote the welfare of the group in competition with other groups, even when it damages the welfare of the person and his or her kin? If so, does the theory of natural selection have to be revamped to designate “groups” as units of selection, analogous to the role played in the theory by genes?

No, groups do not play a role analogous to genes. But that isn’t what group selection is about. Here’s the very short version:

Genes are the basic units of heritable information. Genotypes, however, are not directly exposed to natural selection. Genotypes are exposed to selection via the phenotypes to which they give rise. The question we are concerned with in the group selection debate boils down to “Phenotypes at which level?” Genes are expressed at varying levels of organization. Any particular cell has a phenotype. If we’re talking about multicellular organisms, we can talk about the phenotype of the organism. If we’re talking about multicellular organisms that occur in groups, we might also talk about the phenotype of the group. At which levels can natural selection apply, and, for any particular trait of interest, which level is most appropriate and enlightening? The “pro” argument on group selection boils down to: In some cases, discussing selection at the level of group phenotypes is both accurate and the best way of understanding what’s going on. The “con” side boils down to: It is never appropriate to talk about selection at the level of group phenotypes.

There’s a lot more nuance to it than that, of course, but the basic idea is that we’re talking about gene expression at different levels of organization. Steven Pinker gets it wrong in the third sentence of this article, and perpetuates that error throughout the article. As a result, I find Pinker’s criticisms largely unintelliglble. This is too bad, as in his other writings I’ve found him cogent and compelling.

Jerry Coyne has also been making criticisms of group selection that I find confused or poorly-expressed, but his errors are more sophisticated. I may get to them later.