Paul E. Meehl: Smartest Psychologist of the 20th Century?
I explore a claim made by an undergraduate teacher almost 40 years ago.
Posted Feb 08, 2014
In 1975, my undergraduate abnormal psychology teacher, Neil P. Young, made a claim that I will never forget: that Paul E. Meehl of the University of Minnesota was "the smartest living psychologist." I cannot remember how many reasons Dr. Young gave to support his claim. The only explanation I remember him giving concerned an informal study that Meehl conducted in which Meehl successfully predicted that the wall plaques in the stairwell of the Washington Monument would show more financial donations from fire departments than police departments.
It is easy to make a psychological prediction that seems plausible from common sense. For example, it is easy to predict that a valid measure of conscientiousness (one of the five major personality factors) will predict students' grade point averages. We all know that earning high grades depends on self-discipline, perseverance, being well-organized, and hard work—all aspects of conscientiousness. Unsurprisingly, a meta-analytic review of 51 studies confirms common sense: conscientiousness indeed predicts GPA. What is perhaps surprising is that 51 studies were conducted to confirm what we already knew from common sense.
So, how was Meehl able to make a prediction that was not like to occur to any other living psychologist? Because he was very intelligent? Creative? Perhaps, but "intelligence" and "creativity" are just short-hand descriptions summarizing his ability to come up with clever ideas. In what particular way was Meehl smart or creative?
According to Neil Young, what really helped Meehl was his extensive familiarity with Freudian theory, both as an academician and a practicing psychotherapist. Now, I do not want to make this post and its comments an argument about the merits and shortcomings of Freudian theory. That is an old and boring debate. I only want to explain what it is about Freudian theory that enabled Meehl to make his prediction: that the theory contains genuinely theoretical constructs that are unobservable in everyday experience.
Note that Meehl's successful prediction is not proof of the validity of psychoanalytic theory. (Proving theories is not what science is about.) Rather, it shows the power of Freud's theory to generate a testable prediction that is totally unobvious from common sense, due to the theory's employment of constructs not present in everyday, ordinary awareness. That is what powerful theories do; they allow us to create hypotheses that are impossible to imagine from common sense. Part of Meehl's intelligence was recognizing and employing the power of Freud's theory.
(As an aside, hopefully not detracting too much from this post about Meehl, I think that the theory of evolution through natural selection is a much better, more powerful theory than Freud's. Evolutionary theory has certainly generated many more non-obvious predictions that have been confirmed by empirical observation. In the words of Edouard Machery, evolutionary theory is "psychology's best discovery heuristic.")
But perhaps my favorite Meehl essay was his very first publication (1945, Journal of Clinical Psychology), which was instantly a classic: The Dynamics of "Structured" Personality Tests. In this brilliant piece, he explains why it is naïve to assume what people are thinking and feeling when they respond to items in self-report personality tests. This article has been an inspirational influence on my own research program on the dynamics of personality testing.