If you’re looking for insight into the true you, there’s a buffet of personality questionnaires available. Some are silly—like the internet quiz that tells everyone who takes it that they are procrastinators at the core. Other questionnaires, developed and sold as tools to help people hire the right candidate or find love, take themselves more seriously.
The trouble is, if you ask the experts, most of these might not be worth the money. “You should be skeptical,” says Simine Vazire, a personality researcher at the University of California, Davis. “Until we test them scientifically we can’t tell the difference between that and pseudoscience like astrology.”
One famous example of a popular but dubious commercial personality test is the Myers–Briggs Type Indicator. This questionnaire divides people into 16 different “types” and, often, the assessment will suggest certain career or romantic pairings. It costs $15 to $40 for an individual, but psychologists say the questionnaire is one of the worst personality tests in existence for a wide range of reasons. It is unreliable because a person’s type may change from day to day. It gives false information (“bogus stuff,” one researcher puts it). The questions are confusing and poorly worded. Vazire sums it up as “shockingly bad.”
Personality questionnaires began evolving about a century ago, says Jim Butcher, an emeritus psychologist at the University of Minnesota. “They started asking questions about an individual’s thinking and behavior during World War I,” he says. “These were to study personality problems and mental health problems.” And importantly, he adds, the U.S. military wanted the questionnaires to help weed out soldiers who weren’t fit to fly military aircraft.
According to Butcher, during the first half of the 20th century many academics started creating different personality scales. “Not just on mental health diagnoses, but what personality is like,” he says. The problem with practically all of the assessments at the time was they were a built on the creators’ subjective feelings about personality, he notes. “Then people started to raise questions about do they really measure what they think they’re measuring? How reliable are those conclusions, and are they valid?”
Vazire says in developing the Big 5 Personality model, psychologists tried to avoid pitfalls that plagued early personality researchers—like selecting criteria based primarily on intuition. Instead, the Big 5 model took a holistic tack by compiling every word that could be considered a personality trait and creating simple, straightforward questions about them. For example, on a scale of 1 to 5, are you outgoing, sociable? Have a forgiving nature? Based on how people answered initial surveys, researchers used statistical methods to group traits that seemed to cluster together (like “talkative” and “sociable”) into five basic categories: extraversion, conscientiousness, agreeableness, neuroticism and openness to experience. The other model, the HEXACO model of personality structure created in 2000 by psychologists Kibeom Lee at the University of Calgary and Michael Ashton at Brock University in Ontario, is similar but adds an extra category: honesty–humility.
There are other reasons why Stein thinks some personality assessments may be pseudoscientific. “What those tests will tell people is true or false is determined by what people are willing to pay for,” he says. “Their process as a company is to tell people whatever will sell the product.” By contrast, the Big 5 and HEXACO models were shaped by an empirical process and independent peer review that showed people’s scores tended to be consistent, and predictions made using the models are reproducible. Without that, Stein says personality tests should be treated with extreme suspicion.