Why do we like personality tests?

I’ve taken two personality tests this month, because of a couple of work initiatives. One was related to the ‘Big Five’ model of personality traits, which are:

• extroversion,
• neuroticism,
• agreeableness,
• openness to experience, and
• conscientiousness.

The idea is we all score somewhere on a spectrum of each of the Big Five, (which stem from work by Eysenck and were developed by Costa and McCrae). Where we land on these dimensions determines our personality and predicts our reactions in different situations.

Personality tests are still used loads in business and recruitment settings, even though there is very limited evidence that they link to job performance (Morgeson et al, 2007).

There is also mixed evidence on whether personality is a stable construct. Despite the adage that leopards can’t change their spots, repeating personality tests over time show results can and do change. This seems to relate to age and also social context. Formerly people thought changes in personality happened more pre-30, but in fact changes in scores on these measures go on throughout life. A nice longitudinal study by Helson et al (2002) showed that scores on measures of dominance and independence, for example, tended to peak in middle age, which makes sense in relation to Western social expectations.

All of which I find reassuring, because my results on the Big Five measure have changed since I last completed it, about ten years ago, as an Undergraduate. My Openness to Experience score has soared through the roof, and my Conscientiousness score, which used to be sky-high, is now Average. (Average!)

So we can interpret that in a variety of ways: my self-report this time round might have been done on a day I felt particularly lackadaisical about work and keen to try new things, or my personality might have changed in the last ten years. In the end it is probably a bit of both, and one questionnaire isn’t going to reliably speak to the complexities of my responses.

So why do we like these tests so much if the results can change and don’t necessarily reflect how good we are at our jobs anyway? They are easier, in recruitment settings, than spending hours in interview. They reassure recruiters that they are making evidence-based decisions. But maybe we also like them for the same reasons we fill in quizzes and read our horoscopes.

Maybe we like the idea that someone can hold a mirror up to our internal world as well as our exterior. This is what ‘good enough parenting‘ does for infants: reflects back a baby’s emotions and puts them into words. A sensitive parent helps us understand ourselves as well as the world around us by this naming of what we feel. No wonder we like an echo of this. We need to be careful though… Parents don’t always get it right and if they can fail what chance does a questionnaire have? We can’t really rely on a test to necessarily be accurate to the sensitivities and complexities of who we are, although they can give us a valuable spring board to think from. My advice would be to use the questionnaires, to reflect on what you think about what they tell you, but to take it all with a healthy pinch of salt.