Heuristic purposes of the distinction: Clarifies the analysis of seemingly irrational social patterns.  In the first place, the distinction aids the sociological interpretation of many social practices which persist even though their manifest purpose is clearly not achieved.  The time-worn procedure in such instances has been for diverse, particularly lay, observers to refer to these practices as "superstitions," "irrationalities," "mere inertia of tradition," etc.  In other words, when group behavior does not--and, indeed, often cannot--attain its ostensible purpose there is an inclination to attribute its occurrence to lack of intelligence, sheer ignorance, survivals, or so-called inertia (1968, p. 116).