Meehl on theory testing, never gets old.

The position of Popper and the neo-Popperians is that we do not “induce” scientific theories by some kind of straightforward upward seepage from the clearly observed facts, nor do we “confirm” theories as the Vienna positivists supposed. All we can do is to subject theories—including the wildest and “unsupported” armchair conjectures (for a Popperian, completely kosher)’— to grave danger of refutation…

A theory is corroborated to the extent that we have subjected it to such risky tests; the more dangerous tests it has survived, the better corroborated it is. If I tell you that Meehl’s theory of climate predicts that it will rain sometime next April, and this turns out to be the case, you will not be much impressed with my “predictive success.” Nor will you be impressed if I predict more rain in April than in May, even showing three asterisks (for p < .001) in my t-test table! If I predict from my theory that it will rain on 7 of the 30 days of April, and it rains on exactly 7, you might perk up your ears a bit, but still you would be inclined to think of this as a “lucky coincidence.” But suppose that I specify which 7 days in April it will rain and ring the bell; then you will start getting seriously interested in Meehl’s meteorological conjectures. Finally, if I tell you that on April 4th it will rain 1.7 inches (.66 cm), and on April 9th, 2.3 inches (.90 cm) and so forth, and get seven of these correct within reasonable tolerance, you will begin to think that Meehl’s theory must have a lot going for it. You may believe that Meehl’s theory of the weather, like all theories, is, when taken literally, false, since probably all theories are false in the eyes of God, but you will at least say, to use Popper’s language, that it is beginning to look as if Meehl’s theory has considerable verisimilitude, that is, “truth-like-ness.”

Meehl, P. E. (1978). Theoretical risks and tabular asterisks: The slow progress of soft psychology. Journal of Consulting and Clinical Psychology, 46, 806–834. doi:10.1037//0022-006X.46.4.806

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Can Theory Change What it is a Theory About?

In Beyond Freedom and Dignity B.F. Skinner writes, “no theory changes what it is a theory about; man remains what he has always been.” By this Skinner means that the underlying rules or processes that guide human behavior are constant, and that knowledge of these processes does not change their nature. However, throughout the social psychological literature we see suggestions of just the opposite—knowledge of a psychological process can change the psychological process. For example, Schmader (2010) provides evidence that simply teaching people about stereotype threat may “inoculate them against its effects.” The theory of social identity threat postulates that people are sensitive to contexts that threaten their identity, and when such a situation is detected people engage in ruminative conflict that can distract them enough to undermine their performance in that setting. Schmader is claiming that giving people knowledge of psychological processes predicted by theory changes the processes that unfold. This point raises several important questions: what is a psychological theory? Does psychological theory describe stable processes in the Skinnerian sense? Can we think of psychological theory in the same way that we think about theories of say physics or biology? If we believe theory must have some element of stability (e.g., if we believe light traveled at the same speed in the middle ages as it does today), and that theories exist out side of and are independent from our knowledge of their existence (e.g. the theory of special and general relativity existed before Einstein identified them, and his discovery did not change their quality), then can we classify social psychological theories as theories? My sense is no. Or maybe we need to modify our definition of what qualifies as a theory. Or perhaps our definition of stability in the processes that underlie phenomena and our belief that observation is independent from underlying processes needs modification.

References

Schmader, T. (2010). Stereotype Threat Deconstructed. Current Directions in Psychological Science, 19, 14–18. doi:10.1177/0963721409359292