Pragmatic factors of deontic reasoning

A thesis submitted in partial fulfilment of the requirements of the University of Wolverhamptonfor the degree of Doctor of PhilosophyThis thesis is concerned with pragmatic factors of deontic reasoning, namely scale of violation, aggravating and mitigating circumstances and power of source. Nine experiments are reported investigating deontic reasoning and judgement revision. Experiment 1 established scale of violation as a modifying factor of a working rule with an inferential reasoning task, however, the effects were not transferred to a deductive reasoning task in Experiment 2. Scale of violation and circumstances were found to influence the reasoning of motoring violations with a major offence and aggravating circumstances being rated as more serious and receiving greater fines than a minor offence or mitigating circumstances (Experiments 3 & 4). These effects were also observed with a judgement revision task (Experiment 5). Power of source was included as an additional pragmatic factor and was found to influence the reasoning of conditional statements (Experiment 6), inducements (Experiment 7) and ratings of credibility and probability of outcomes (Experiment 8). The final study (Experiment 9) found significant effects for scale of violation / compliance and power of source within a judgement revision task. However, no difference was observed in the reasoning of superordinate and non-superordinate statements. The findings are explained in terms of the conditional probability hypothesis