Another Look at Meehl, Lakatos, and the Scientific Practices of Psychologists Reuven Dar University of Wisconsin--Madison ABSTRACT: This article examines current research methodology in psychology in the context of Serlin and Lapsley's response to Meehl's critiques of the scientific practices of psychologists. The argument is made that Serlin and Lapsley's appeal to Lakatos's philosophy of science to defend the rationality of null hypothesis tests and related practices misrepresents that philosophy. It is demonstrated that Lakatos in fact considered psychology an extremely poor science lacking true research programs, an opinion very much in line with Meehl's critique. The present essay speculates on the reasons for Lakatos's neg- ative opinion and reexamines the role of null hypothesis tests in relation to the quality of theories in psychology. It is concluded that null hypothesis tests are destructive to theory building and directly related to Meehl's obser- vation of slow progress in soft psychology. In a recent article Serlin and Lapsley (1985) reviewed Meehl's (1967, 1978) critique of the scientific practices of psychologists. According to Serlin and Lapsley, some of Meehl's criticism is not justified; specifically, they sug- gested that from the perspective of the philosophy of sci- ence developed by Imre Lakatos (1978a), most of the actual practice of scientific psychology can be rationally defended. The present article is an attempt to further examine Meehl's critique and Serlin and Lapsley's defense of sci- entific psychology, particularly of the use of null hypoth- esis tests. In the following pages I argue that although Serlin and Lapsley's examination of the rationality of re- search methodology in psychology is important and timely, the conclusions they drew in regard to this ex- amination are a bit too positive. I take issue with some of Serlin and Lapsley's points, particularly with their in- terpretation of Lakatos's philosophy as it applies to sci- entific psychology. I also try to offer an additional per- spective on the issues raised by Meehl and particularly on the implications of null hypothesis testing for the re- search in "soft" psychology. First, however, it is necessary to review briefly the critique offered by Meehl, on the one hand, and Serlin and Lapsley's response, focusing on their appeal to Lakatos's philosophy, on the other. Meehl's Critique and Serlin and Lapsley's Response Meehrs original critique of theory testing in psychology (Meehl, 1967) was focused on what Serlin and Lapsley (1985) called "the asymmetry argument (p. 74)." Meehl observed that whereas physicists derive and test point predictions, psychologists do the opposite: They test the theory by attempting to reject a point-null hypothesis, which is the logical complement of the theoretical pre- diction. This, argued Meehl, leads to the paradox that in psychology, increased measurement precision makes it easier for the theory to pass the test, whereas in physics it increases the severity of the test, as presumably it should. The tests to which theories in psychology are subjected, wrote Meehl, are so easy that passing them is "only an extremely weak corroboration of any substantive theory" (Meehl, 1967, p. 111). This problem is compounded, ac- cording to Meehl, by the practice of evaluating a theory by "counting noses," that is, comparing the number of experimental 'confirmations' to the number of 'refuta- tions' of the theory under test (p. 112). This, said Meehl, is scientifically preposterous, because, as deductive logic dictates, refutations are much more critical to the validity of a theory than confirmations. An additional problem is that the typical theory in psychology is only loosely associated, through its "auxiliary hypotheses," to its op- erations in the experiment. This, according to Meehl, means that the results of the experimental test, which is absurdly easy to begin with, have no real impact on the substantive theory itself. It also leads to excessive ad hoc theorizing in which the auxiliary hypotheses are chal- lenged and tested repeatedly while the substantive theory is left behind, never subjected to a risk of refutation. More recently, Meehl (1978) criticized the slow, noncumulative scientific progress in "soft" psychology. Elaborating on his 1967 arguments, Meehl tied this slow progress to faulty scientific methodology and especially to the reliance on null hypothesis tests. Serlin and Lapsley's (1985) article has two distinct components. On the one hand, the authors agreed with Meehl on the need to increase the severity of the tests to which psychologists subject their theories; to that end they proposed the methodology of the "good-enough princi- ple," which is a most sophisticated solution to this prob- lem. On the other hand, they rejected other aspects of Meehl's critique by appealing to Lakatos's (1978a) views on the history and philosophy of science; this latter com- ponent is the focus of the present essay. Serlin and Lapsley (1985) responded to Meehl's cri- tique with an attempt at "reconstructing the actual prac- tice of psychologists into a logically defensible form" (p. 73). They asserted that null hypothesis testing, in prin- ciple, is necessary and should be a part of the methodology of the hard as well as the soft sciences. They also suggested February 1987 American Psychologist Cog/right 1987 by the American l~ychologieal Association, Inc. 0003-066X/87/$00.75 Vol. 42, No. 2, 145-151 145