Scepticism as to whether people understand either their cognitive activity or the causes of their behaviour has been articulated afresh by researchers in social psychology in the 1970s and 1980s (e.g., D. J. Bem, 1972; Nisbett and Wilson, 1977; Wilson, 1985; Wilson and Stone, 1985). This new affirmation of the sceptical stance derives its impetus from research and theories in social psychology. A synthesis of these theories was persuasively presented in Nisbett and Wilson's (1977) review of research that examined verbal reports; according to Nisbett and Wilson, this research shows that actors' understanding of their behaviour is no better than that of observers. This conclusion was compelling partly because it reinforced the predictions of D. J. Bem's (1967, 1972) self-perception theory, which proposes that actors' and observers' attributions for actors' behaviour should not significantly differ. This lack of difference was predicted on the assumption that the causes of behaviour are publicly available, in the form of stimuli and cultural norms, rather than being hidden inside the actor's head.

Any research supporting this sort of conclusion carries significance as it bears on the perennial philosophical—psychological issue of the causes and the explanation of behaviour. The major views on this issue were reviewed in chapter 2.