As the Scottish independence referendum campaign enters its final stages, both sides will still be hoping that they can persuade as many voters as possible that their side is right. Although undoubtedly some voters are still to decide which way they will vote, the minds of most voters were made up long ago and the campaign will have made little difference. Political psychologists have convincingly shown that voters aren’t particularly good at making objective assessments of arguments about political issues – regardless of their actual validity, we tend to think that arguments that support our positions are good and arguments that don’t are bad. Even when voters have the same factual information, partisan bias leads to very different conclusions. The stability of the referendum polls despite the long and intense campaign suggests that these factors are almost certainly playing an important role in opinions on the independence debate.
If vote intentions in the referendum aren’t a result of objective evaluations of the pros and cons of Scottish independence, where do these opinions come from? Political attitudes are not simply created in a vacuum, nor do they just reflect self-interest according to socio-economic position. Scholars have long suspected that political attitudes arise from deep-seated psychological dispositions – particularly from differences in personality. For psychologists, ‘personality’ captures the patterns of thought, feeling, and behaviour that are relatively stable within individuals in different situations and across time: people who are organised at work are also likely to be organised at home; shy children often grow up to be shy adults. For the past few decades, the leading paradigm in personality psychology has been the ‘Big Five’ approach, which has shown that much of the variation in personality traits between people can be captured by five dimensions – agreeableness, conscientiousness, emotional stability (sometimes labelled ‘neuroticism’), extraversion, and openness to experience.