Since 1970, J. A. Gray (1970, 1981, 1982, 1987a) has outlined several aspects of a personality model called Reinforcement Sensitivity Theory (RST). This model has generated a great amount of experimental research and has been applied to adult psychopathology (Fowles 1988), psychophysiology (Fowles 1980), child psychopathology (Quay 1988; Nigg 2000, 2001) and disinhibited behaviour (Patterson and Newman 1993). The impression one has thirty years on, however, is that the model still has some grey areas since it was first proposed, which are lacking in detail and in some ways limit its development (see Pickering, Corr, Powell, Kumari, Thornton and Gray 1997).
Theoretical contributions and controversial issues of RST
Considering basically performance and conditioning studies, the aim of the present chapter is to raise some of the model's problematic aspects and to put forward some hypotheses and practical issues in regard to its application to humans. The chapter begins by setting out Gray's model in its initial formulation, and further theoretical contributions (Corr 2002, 2004; Patterson and Newman 1993; Wallace and Newman 1990). We shall then deal with aspects which we consider essential with regard to application to humans, and compile the results of the research work in this field from a new point of view. Owing to the fact that measures of BIS and BAS are based on Gray's classical model (Gray 1982), and that it remains to be seen how the new model by Gray and McNaughton (2000) fits in, the basis of this review will be the classical RST model.