The strange beliefs and practices of personality testing
Is there any science behind your test?
Personality tests intrigue because they offer the chance to know ourselves and to understand others. This is important when hiring people who may look good, but are an unknown quantity. But is the test you are using as useful as you hope it is?
Do you know your blood type? Did you know that your blood type might explain why you are aggressive or submissive (types A and O respectively)? Not important? What if your school-aged child was bullied because he or she was of the rare and mysterious blood type AB? Or your older child, as an individualistic and selfish type B, was told their marriage prospects were limited? Or you missed assignment to a high profile project because your blood type didn’t fit?
This is not a brief for a weak dystopian drama. It is what life can be like in Japan (and South Korea and Taiwan). The blood type theory of personality is not based on any science. But it is perpetuated through manga storylines, best-selling self-help books and popular magazines. Facebook provides northern Asians with the option to include their blood type in their profile.
Again, there is no evidence that blood type makes any difference to personality or behaviour. But the belief that it does has real effects in these countries. The weirdness of such beliefs and the shock of realizing their real-world implications hit us as outsiders looking in. Are there similar approaches or beliefs in our society that we can’t see because we are too close to them?
France provides another example. Thinking of making a high-stakes hire in your business? Of course, you’d require short-listed candidates to write a “motivational letter” and then pass these on to an accredited handwriting analyst. No-one gets hired until the graphologist gives the all-clear. Of course – people’s inner psychology is illuminated by their writing style – the size, shape and slope of the letters, the energy used to form them. No less an authority than Carl Jung provides credibility for this wonderfully French tradition.
Organisational psychologists have a track-record of reviewing the accuracy of different tests and behavioural assessments. They usually reference test results against later job performance. There are so many studies that it is possible to put together uber-reviews combining the results of different studies. Overall the best predictor of job performance is intelligence. The level of job performance explained by IQ can go up to around 50% for more complex jobs. That might not seem like a big amount but it adds value to the selection decision. The quantum of explanation provided by intelligence illustrates the importance of job design, the contribution of managers, and both team and organisational culture in getting great performance from people.
Modern personality tests explain lower levels of job performance than intelligence – up to around 20%. Graphology consistently, across different studies and meta-analyses explains zero per cent of performance. How do graphologists get away with it? Think of that handwriting sample – it provides clues about the candidate in what has been written as well as in the writing itself. Studies where the individual details are stripped out, leaving the graphologist to work with only handwriting show a drop to zero in the graphologists’ accuracy. That means that the graphologist’s recommendation is no better than chance – she or he is just as likely to recommend a poor candidate as a good one.
No accounting for the French eh? But stereotypes aside, why do people persist with discredited and dangerous pseudo-science? Blood type personality was invented in Japan. Graphology in France. Perhaps there is a nationalistic issue. A chauvinism that rejects foreign approaches. Also, there is a nexus of players who have invested careers and reputations in this mumbo-jumbo. Many of them are doing well from it – selling professional services, books and training courses. Of course, it would never happen here, would it?
There is a range of personality assessments available. These can be easily divided into pop and credible tests. What’s the difference? Put Wikipedia to work – what is the independent evidence about this measure? Or try this in your browser: “is there any science behind [XYZ] test.”
One popular personality test that fails these tests is the Myers-Briggs. Since the development of the Myers-Briggs, there has been a gap between what the results demonstrated and what the test developers and users wanted. Mrs Katherine Briggs was confident that people were either one type or another. Either ‘thinking’ or ‘feeling’ for example. Early results showed that people were distributed along the thinking-feeling and other dimensions according to the ‘bell curve’ that is typical of many natural phenomena. Most people are a bit of a thinker and a bit feeling-oriented, only those at the extremes are one or the other. According to biographer Merve Emre, Mrs Briggs parted company with the research scientists and pushed ahead with her model putting people into boxes – one of 16 boxes.
As the most popular personality test the Myers-Briggs has got something going for it. A 1991 report by the US National Academy of Sciences notes: “the troublesome discrepancy between research results (a lack of proven worth) and popularity.”
The lack of connection between scores on the Myers-Briggs and real-world results, such as job performance means that those selling and otherwise promoting the Myers-Briggs can’t claim that it has any use beyond being a talking point.
From the 1990s psychologists agreed on a ‘Big Five’ approach to measuring personality. People vary along the five personality dimensions of open-minded, conscientious, extrovert, agreeable and the unfortunately named neurotic (think “sensitive”). Test developers have built nuanced, job- and life-relevant tests from this foundation. Put “research into big five personality” into your browser – you’ll get 211 million hits.
We have learned that personality flexes according to the challenges we face. People starting work and learning to get things done increase in conscientiousness. Those put into supervisory roles and guiding workers become more extroverted. More open-minded people have higher levels of demonstrated creativity (books written, patents filed, art created) over their 45-year post-university career. Highly agreeable people perform well in customer service jobs. In contrast populist or ‘strongman’ leaders are very low on ‘agreeableness.’ Mountain climbers at Everest base camp are less neurotic – in other words not all that sensitive to risk!
If you want to learn more about someone, or even yourself, you’ll get more of a realistic view from a modern personality assessment, which is based on valid personality theory and which passes the test of being based on science.
Stewart Forsyth is an organisational psychologist and executive coach and author of the eBook 21 Remarkable People.
Image: one of many personality profiles from 21 Remarkable People
