by Greg Mayer

Jerry has posted a few times (here, here, and here) about a paper in Nature by Nowak, Tarnita and Wilson which claims that kin selection is a concept of little or no value. Several critiques of this paper are now in press in Nature, including one by Abbot et al., of which Jerry is a coauthor, along with 136 others. In mentioning his paper here at WEIT, Jerry wrote

The list of authors and their institutions, which occupies two pages of the three-page letter, reads like a Who’s Who of social evolution.  It’s telling that nearly every major figure in the field lined up against Nowak et al.

WEIT reader Dr. I. Needtob Athe commented on this that

I’m confident that you’re on the right side of this dispute, but still, that argument is uncomfortably reminiscent of an infamous book titled “Hundert Autoren gegen Einstein” (Hundred authors against Einstein) [1931.]

The commenter implies that the number of people supporting a proposition is not an argument in its favor, which logically, of course, it isn’t. It’s the well-known logical fallacy of argumentum ad populum. As Jerry rightly pointed out, that doesn’t mean the proposition is wrong, either (which commenters humorously denoted the argumetum contra populum or argumentum nonpopulum).

The more interesting issue to my mind though is that there is a pragmatics, as well as a logic, of argument. Most of what we hold to be well supported propositions are based not on arguments or evidence directly examined by us, but are based on evidence or experience of others.

I’ve never been to London. If pressed, though, I could put together a pretty good case for its existence. Much of my case would depend upon the use of expert or reliable sources. While logically such arguments do not compel assent, they are nonetheless valuable, and provide a pragmatic guide to assessing claims.  Bertrand Russell, I think, got the pragmatics of assessing expert opinion right in Let the People Think (1941):

(1) that when the experts are agreed, the opposite opinion cannot be held to be certain; (2) thet when they are not agreed, no opinion can be regarded as certain by a non-expert; and (3) that when they all hold that no sufficient grounds for a positive opinion exist, the ordinary man would do well to suspend his judgment.

Note that Russell advises us on how to apportion our doubt, rather than our belief– a pragmatics of skepticism, rather than belief.

We must also ask who is an expert. Maria Reichenbach, in an introduction to her husband, Hans Reichenbach‘s, The Theory of Relativity and A Priori Knowledge (U. Cal Press, 1965), writes of 100 Autoren gegen Einstein this way:

In contrast to philosophers sympathetic to Einstein’s ideas were philosophers of the more speculative bend who tried to refute his theory. A collection of articles pretending to disprove the theory of relativity is entitled  100 Autoren gegen Einstein. The tenor and content of these “contributions” sound unbelievable if not intentionally funny from our present viewpoint.

So, the hundred authors are not physicists, but mostly philosophers. But expertise in one area does not necessarily translate into expertise in all (think William Shockley).

The take home message then is not that Jerry and 136 other evolutionary biologists are right by virtue of their numbers; but rather that the fact that (nearly) all experts agree means that we cannot hold the contrary view  (that of Nowak et al.) to be certain.

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Abbot, P. et al. 2011. Inclusive fitness theory and eusociality. Nature 471: in press. (abstract only)

Nowak, M. A., C. E. Tarnita and E. O. Wilson.  2010.  The evolution of eusociality.  Nature 466: 1057-1062. (abstract only)