Corrections to the blogosphere, the consensus, and the world

Tuesday, December 04, 2012

Someone on the Conversation leads with his chin.

In his attempts to prove that psychology is a science Scott works on the basis of the all to frequent syllogism

  1. Science is a good thing
  2. Psychology is a good thing
  3. Therefore psychology is a science. 

He says "Many other criticisms of psychology’s scientific status are largely misguided. ... psychology has made myriad contributions to society that most of us take for granted... Psychologists have been on the forefront of advances in advertising, education, achievement testing, political polling, psychotherapy, animal training, airplane cockpit safety, and scores of other domains".  What do any of these have to do with scientific status?

Physics isn't a science because of its achievements in timekeeping, navigation, and inflating balloons, it's a science because it claims to give us access to the way the world is underneath the appearances. It is a successful method of generalisation.

Psychology isn't a science, whatever its achievements in cockpit safety, because all its statistics fundamentally rest on what people say to it; and people are unable to be standardised to the point where they can be meaningfully compared. Specifically, if in a physics experiment the researcher records that their samples fell upward one can be reasonably confident that the outcomes were impossible. If, in the example Scott gives, a researcher tests earthquake victims in Iran and records that the number of people experiencing PTSD is not 25.26% but rather 2.5% or 75.78% then one cannot be confident that the outcomes are impossible. Rather, new hypotheses would be added - Iranians are different, earthquakes are different, researchers are different.

Basically, Scott says that psychology - or at least good psychology, the kind he does - is scientific because it uses scientific methods. The underlying problem, though, is that he can appeal to no criterion to discriminate between two scientifically conducted psychology experiments that produce conflicting results.  There is no underlying structure of theory.

Over the past century psychology, after all, has had two grand theories -- Freudianism and behaviourism - sunk under it, and has replaced them with nothing. The IQ test, its main instrument over that time, has been holed beneath the waterline by the Flynn effect. Scott boasts that psychology has disproved the dictum that opposites attract; this is hardly comparable to the atomic theory or quantum chromodynamics. Where are the important truths?

Even Scott's pretty damn trivial claims tend to shrivel under closer examination. His link for the value of psychology in"teaching language to children with autism' goes not to any articles on this topic but to another general isn't-psychology-wonderful puff piece - probably a good thing, given the extreme weakness of the evidence on ABA in this area (see Michelle Dawson at He says
Carefully measured personality traits such as conscientiousness are moderately good predictors of performance in just about every occupation; and pathological traits such as psychopathy (a constellation of features that comprises charm, guiltlessness, callousness, and poor impulse control) are consistent predictors of violence and criminal recidivism.
but conscientiousness is a component of performance, not an unrelated variable, and logically has to be associated, while the relationship between psychopathy and violence is almost washed out by the cultural differences in violence rates between, say, Japan and Columbia.

I'm sure psychology has some successes.  It's virtually impossible to imagine an enterprise of that size running for a hundred years and producing absolutely nothing. This is some way, however, from saying that the enterprise was worth the resources that have been put in to it (and are now being put in to it). How many people across Australia should be trained to staff airplane cockpit institutes (etc., perhaps)? Under four thousand a year, I would have thought, which is the number graduating now. And it certainly doesn't establish that the jerry-built 'sprawling confederation' of psychology constitutes a science, or ever could.

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