The four temperament dimensions of the psychobiological model are hypothesised to be associated with genetically independent neurobiological systems. Individual differences on these dimensions are thought to be the basis of individual variation in personality (Cloninger, 1986). Novelty Seeking reflects the tendency to respond strongly to novelty and cues for reward as well as relief from punishment, and is thought to play a role in the activation or initiation of behaviours. Harm Avoidance reflects the tendency to respond strongly to aversive stimuli, which leads to learned inhibition of behaviour, and is thought to play a role in the inhibition or ceasing of behaviours. Reward Dependence reflects the tendency to react strongly to rewards and to maintain behaviours previously associated with reward or relief of punishment, and is thought to play a role in the maintenance or continuation of behaviour (Cloninger, 1986, 1987). Persistence reflects the tendency to persevere despite frustration and fatigue (Cloninger, et al., 1993).
