The theoretical ambition of behavioural science

From Richard Posner (HT: Ryan Murphy):

[Behavioral economics] is undertheorized because of its residual, and in consequence purely empirical, character. Behavioral economics is defined by its subject rather than by its method and its subject is merely the set of phenomena that the most elementary, stripped down rational-choice models do not explain. It would not be surprising if many of these phenomena turned out to be unrelated to each other, just as the set of things that are not edible by man include stones, toadstools, thunder-claps, and the Pythagorean theorem. Describing, specifying, and classifying the empirical failures of a theory is a valid and important scholarly activity. But it is not an alternative theory. …

The behavioralists’ lack of interest in, and indeed hostility to, evolutionary theory is an example of their lack of theoretical ambition. But it is more. Most though by no means all behavioralists are political liberals. The use of evolutionary theory to explain human social rather than merely physical traits, the use that goes by the name “sociobiology” (recently renamed by its proponents “evolutionary ecology” because of the negative connotations that “sociobiology” had acquired among the politically correct) is anathema to liberals - as, indeed, is economics; and much of “behavioral economics” is really anti-economics. Political bias is especially conspicuous in the neglect by the behavioralists of vengeance, though it is the best attested example of the “fairness” instinct. Liberals do not like vengeance and prefer to think that our instinct for fairness is dominated by altruistic concerns that might provide a foundation for organizing society along socialist or collectivist rather than free-market lines.

The rest of the article is worth a read, although Posner’s defence of rationality is a touch too much.