Personality Matters In Attitude

The ability to reason depends on intelligence, but preferences for different sorts of reasoning may depend on an individual’s personality. The possibility is unlikely if reasoning is akin to a formal proof in logic. But, such effects are predicted from the theory that reasoning is a semantic process of envisaging possibilities consistent with the meanings of premises and knowledge. According to the standard ‘big five’ model of personality, individuals differ in their openness to experience and in their conscientiousness. Certain inferential problems are ambiguous, e.g., if a pilot falls from a plane without a parachute then the pilot dies; this pilot didn’t die; how come? A deductive response is: the pilot didn’t fall from a plane without a parachute; an inductive response is: the plane was on the ground. Highly conscientious individuals who are also less open to experience should focus on the possibilities consistent with the premises, and tend to make a deduction, whereas those who are open to experience and not very conscientious should go beyond these possibilities, and tend to make an induction. Here we show that these biases occurred both for stable personality traits and for the same attitudes induced experimentally, either from false feedback about performance in a personality test or from participants’ recall of autobiographical episodes illustrating the required attitudes. Researchers have often assumed that reasoning is a universal akin to the ability to use natural language. They have also assumed that personality traits are stable with constant effects on cognition and behaviour. Our results imply that neither assumption is invariably correct. They also corroborate the semantic view of human reasoning, and may lead to the discovery of other effects of personality traits, such as extraversion and neuroticism, on reasoning.