Methodological fetishism

Taking a break from the idea of social science I read a bit more of McManus's Heidegger and the Measure of Truth only to find him talking about social science too. On pp. 156-158 McManus talks about "methodological fetishism" in connection with psychology. (The idea is similar to what Jon Cogburn calls the quantitative fallacy.) Such fetishism involves imposing a model, perhaps a mathematical one, on factors "not obviously capturable in those terms" (p. 157). The result is that what most lends itself to enumeration (in the case of a mathematical model) is then treated as being of greatest importance just because it lends itself to the model being insisted upon. McManus then voices a "routine worry" (p. 157) about whether personality traits as measured by numerical scales of introversion/extroversion, etc. actually tell us anything useful about people in the real world. He connects this general problem also with behaviorism:

In one sense, behaviourism succeeded in describing human conduct using variables that could be handled mathematically. The sense in which it failed was that the variables it used captured aspects of conduct in which no one was interested: what we could measure quantitatively repeatedly turned out to be nothing more than weakly associated with what we wanted to have measured. This realization took a long time to emerge, and its precise significance is still disputed. (p. 158)

There is nothing inevitable about this, as McManus and McManus's Heidegger agree. There is no reason a priori why mathematics and science cannot be used to discover truths about reality. But there is equally no guarantee that they will prove useful every time we try to apply them. They are tools that might not be useful for every job. And human behavior looks like being something they are not all that well cut out for.