You may say, “But, Meehl, R. A. Fisher was a genius, and we all know how valuable his stuff has been in agronomy. Why shouldn’t it work for soft psyc… - Paul E. Meehl

Most so-called “theories” in the soft areas of psychology (clinical, counseling, social, personality, community, and school psychology) are scientifically unimpressive and technologically worthless. [...] Most of them suffer the fate that General MacArthur ascribed to old generals—They never die, they just slowly fade away.

the null hypothesis in the life sciences is almost always false—if taken literally— in designs that involve any sort of self-selection or correlations found in the organisms as they come, that is, where perfect randomization of treatments by the experimenter does not exhaust the manipulations. Hence even “experimental” (rather than statistical or file data) research will exhibit this if interaction effects involving attributes of the persons are studied. Consequently, whether or not the null hypothesis is rejected is simply and solely a function of statistical power.

Because physical theories typically predict numerical values, an improvement in experimental precision reduces the tolerance range and hence increases corroborability. In most psychological research, improved power of a statistical design leads to a prior probability approaching ½ of finding a significant difference in the theoretically predicted direction. Hence the corroboration yielded by "success" is very weak, and becomes weaker with increased precision. "Statistical significance" plays a logical role in psychology precisely the reverse of its role in physics. This problem is worsened by certain unhealthy tendencies prevalent among psychologists, such as a premium placed on experimental "cuteness" and a free reliance upon ad hoc explanations to avoid refutation.