The venerable history of "rhetorical experiments"

Daryl Bem was already rather infamous before he provided, just this week, this excellent quote:

If you looked at all my past experiments, they were always rhetorical devices. I gathered data to show how my point would be made. I used data as a point of persuasion, and I never really worried about, 'Will this replicate or will this not?'

The quote, from this piece on the history of the reproducibility crisis, has been posted and reposted, sometimes with an expression of anger, sometimes with a sad virtual head shake. The derision is well-deserved in the context of Bem’s final experiments, which attempted to show that ESP exists. But let’s examine what Bem was actually referring to – his earlier career as a social psychologist, a career in which he developed some influential theoretical ideas.

One could argue that Bem’s technique was no less scientific than Galileo’s. Yes, that Galileo, one of the first to use and to champion the experimental method. The following passage is from The Scientific Method in Galileo and Bacon:

The method described by Bem, then, is simply Galileo’s scientific method. Admittedly, Galileo was working at the beginning of the history of mechanics, meaning that there was much low-hanging fruit to be picked by generalizing from a few observations and theoretical insights. Bem was working nearly four hundred years later. And yet, much of Bem’s career is not far from the beginning of the history of the field of social psychology. Bem’s theory of attitude change was published less than two decades after Festinger first advanced the cognitive dissonance theory Bem apparently was reacting against.

I know next to nothing about Bem’s work, but I wouldn’t be surprised if he did gain good insights from intuition and theory, and was quite certain of the value of those insights entirely on that basis, and thus the data was indeed just an afterthought. Kahneman and Tversky too made some of their most important discoveries, I believe (e.g., loss aversion?), by a combination of introspection and reasoning.

I don’t think there’s much good to be said about using this “rhetorical experiments” approach for the effort to establish ESP as a real phenomenon, which Bem intended to be the capstone to his career (his work didn’t establish ESP, but ironically did help spark the reforms that are addressing the reproducibility crisis). I detest p-hacking, HARKing, and data fudging – I continue to be involved (e.g. 1, 2), in several initiatives to combat these phenomena, because I know they have yielded more than one patch of empirical ground, good solid stone on which to build a theory, but that has subsequently turned into a cenote; a deep sinkhole. The cavalier attitude toward methodological rigor implied in Bem’s comments is what gets us into a reproducibility crisis.

Still, propounding a theory on the basis of shoddy evidence has a glorious history in science. Don’t forget it. I’m not sure I want us to lose this data-poor, declamatory tradition. There’s value in getting ahead of the data, even when you don’t have the resources or the skills to collect the data that could falsify your theory. If we can create appropriate space to publish that sort of stuff without the author having to pretend that they have impeccable data, perhaps the pressure to cook the books will lessen.