At Revealing Reality, we’re always interested in how individuals’ personalities shape their behaviour – so much so that we’ve recently been exploring how we can incorporate personality tests into our research to add new layers to our insight.

A particular focus has been the ‘Big Five’ personality model, and how it influences some of the big decisions people take in the course of their lives. So we were really excited to read about the recent BBC/Cambridge University Big Personality Test – a major Big Five exercise thrust into the mass media, and discussed on a national scale, with the potential to significantly advance understanding and interpretation of personality in the UK.

So what exactly has the test taught us?

At the most basic level, it has emphasised the benefits of personality-testing on a large scale. With a total of around 400,000 responses, this fast became the first truly nationwide snapshot of personalities in Britain. Its headline-grabbing success demonstrates the fact that such tests are at their most effective when completed by large groups of people – an individual’s personality score being hard to interpret in relative isolation.

But media coverage of the study has also raised some questions. The BBC have a page that informs you how many ‘life satisfaction points’ you could gain by moving to a region where your personality ‘fits in’. The Scots, we are told, are high in ‘agreeableness’, meaning they tend to be friendly, co-operative and kind, whereas their ‘disagreeable’ counterparts in London are grumpy, quarrelsome and irritable. Given this coverage, plenty of people could be forgiven for upping sticks and moving to the Hebrides.

The trouble is that ‘agreeable’ doesn’t equate exclusively to ‘niceness’; it actually refers to those who have greater concern for social harmony. While some of the facets that make up this trait are hard to construe as anything but positive (altruism, trust) I’m not sure people would say the same about compliance – at least, not once they’ve heard about the research saying that high-scorers on ‘agreeableness’ are more likely to administer apparently lethal electric shocks to strangers under the instruction of an authority figure!

Of course, the Cambridge professor leading this research would be the first to caution against moving house as a result of the study – and doubtless it was partly this over-simplification that helped the test achieve the reach it did.

But still: in gauging the ultimate value of such tests, it is crucial to remember that no aspect of personality is wholly good or bad. All the traits in the Big Five – agreeableness, extroversion, openness, neuroticism and conscientiousness – are fundamentally double-edged. And to my mind, therein lies the real strength of describing individuals’ personalities: not in making value judgements, but in providing another window into the complexity of people’s lives.