Children differ in their initial reactions to novel circumstances. Some children show a propensity to react consistently to novelty and unfamiliarity with initial restraint and avoidance. These children are referred to as temperamentally behaviourally inhibited. In this chapter, the suggestion is explored that behavioural inhibition (hereafter called inhibition) may predispose a child to the development of anxiety disorders. After reviewing research on the temperamental quality of inhibition, three areas of research are described that bear on the relation between inhibition and childhood anxiety disorders. First, studies are described which have examined the hypothesized predictive relation between temperamental inhibition and anxiety disorders. Second, the Behavioural Inhibition System (BIS; Gray, 1987, 1988, 1991) is proposed as a plausible neuropsychological substrate for the predictive association between temperamental inhibition and childhood anxiety disorders. Specifically, it is suggested that an overactive BIS seems to underlie the temperamental quality of inhibition as well as pathological anxiety. Third, research is reviewed which bears on the overactive BIS hypothesis for childhood anxiety disorders.

The literature on the relation between temperamental inhibition and anxiety disorders has been reviewed by others (Biederman et al., 1995; Pollock et al., 1995; Rosenbaum et al., 1993; Turner, Beidel & Wolff, 1996). This chapter reviews the more recent findings and focuses in particular on childhood anxiety disorders. Further, the chapter attempts to link the literature on the temperamental construct of inhibition with the notion of the BIS.