2016 made me reassess an important component of my view of the world. No, not Brexit or Trump becoming President (although, it’s not unrelated).
At the end of 2016, I realized that almost all psychology is pseudo-science. Not hyperbole, not oversold, but pseudo-science.
People used to joke that Parapsychology is the control group for science: i.e., a bunch of people ostentatiously following the scientific method in a situation where every result should come out negative. It’s a null field: the null hypothesis (that there is no effect) is true. Thus, the fact that you can still get positive effects should be worrisome. Turns out the true joke was that psychology is the true control group. Parapsychology was a bad control as most scientists were already predisposed to disbelieve them. Psychology is a much better control.
I had heard of the “Replication Crisis” before, but had not delved into the details. I thought psychology was like microbiome studies: over-hyped but, fundamentally, correct. We may see reports that the microbiome makes you be rude to your uber driver or whatever silly effect. We often read about the effects of the microbiome on obesity, as if it didn’t matter that our diets are not as healthy as they should be and it was all down to microbes. Jonathan Eisen collects these as overselling the microbiome.
Still, to say that people oversell the microbiome is not to say that there is no effect. The microbes do not single-handedly cause obesity, but they have an impact on the margin (a few BMI points up or down), which is enough to be significant for the population. They may not cause nor cure cancer, but they seem to influence the effect of immunotherapy enough that we may need to adjust dosages/drug combinations. And so on…
I thought that when it came to psychology, the same was true: sure, a lot of hype, but I thought there was a there there. There isn’t.
My basic mistake was that I had shared Daniel Kahneman’s view of the situation:
My position […] was that if a large body of evidence published in reputable journals supports an initially implausible conclusion, then scientific norms require us to believe that conclusion. Implausibility is not sufficient to justify disbelief, and belief in well-supported scientific conclusions is not optional. This position still seems reasonable to me – it is why I think people should believe in climate change.
This was exactly my position until I read this long Andrew Gelman post. Since then, I started to read up on this and find that psychology (as a field) has sold us a bill of goods.