An attempt has been made in this paper to account in theoretical terms for the generalised slowness which has been shown in previous work to characterise psychotic patients. Making use of the theoretical framework of modern learning theory, two hypotheses were put forward, relating psychotic slowness respectively to: 1. Lack of drive ( motivation) ; 2. An exceedingly slow rate of dissipation of reactive inhibition. It was deduced from the theorems of learning theory that psychotics should be characterised by very low reminiscence scores on tasks involving massed practice if either of the two hypotheses were correct, and experimental evidence does indeed show that psychotics are differentiated from normals and neurotics in precisely this way. It was then argued that a crucial test between the two hypotheses could be performed by varying the length of the rest period used for establishing reminiscence scores, and it was found that while with short rest periods psychotics showed no reminiscence, they did show very strong reminiscence effects after long rest periods. This is interpreted as irreconcilable with the hypothesis of low drive in psychotics, and may be used as support for the hypothesis that psychotics are characterised by a slow rate of dissipation of inhibition.Abstract Teaser