Why Personality Tests Seem to Read Your Mind

Online personality tests that bill themselves as "scarily accurate" or "the most accurate ever" have been all the rage on the internet and social media lately. You only need to complete one of these tests (perhaps by entering your date of birth, or answering one or two simple questions), and when you go on to read your results, you are often left in awe at the computer's "uncanny" analysis — that sense of "Whoa! That's me, Bingo!" — to the point where you even forward the test to friends. Why are we so captivated by these psychological-analysis tools? Read on, and let us look at what personality-analysis tools can do, and where their limits lie.

How is personality assessed?

Modern psychology divides methods of personality analysis into five broad categories:

1. Interviews, which involve conversing with the interviewee in order to understand their psychological characteristics. For example, the person's preferences, social abilities, or even more deeply held worldviews (such as beliefs about fate, conspiracy theories, or their view of the universe);
2. Direct observation, that is, observing a particular subject's behaviour on site (or via video) — for example, a teacher observing the words and conduct of every student in the classroom and, where needed, coaching the students who are struggling;
3. Behavioral assessment, which is similar to the second category, except that the focus is on measuring how frequently a certain behaviour occurs within a specific time frame — for example, the number of times a student "wanders off" or "interrupts" during class, or a psychotherapist asking how many times negative thoughts arise each day for the person seeking help;
4. Rating scale, in which a particular subject answers a series of questions (the most common being to rate each statement from 1 to 5), after which the score distribution is calculated to arrive at a personality-test result; and
5. Projective test, which involves showing test-takers a set of ambiguous images and then analysing their personality from the content of their answers (such as what object they see) and their reaction times. For example, if across a succession of ambiguous images a person repeatedly fixates on "sexual" elements (such as male or female genitalia), this suggests that they may have experienced sexual assault or other negative sexually related experiences.

Personality-analysis tools arise from our fear of the unknown

Curiosity, and a fear of uncertainty, are common to us all. Our curiosity about things (particularly about "people") stems, to some extent, from our dread of the uncertainty of things, and so we tend to seek out a "magic charm" that can reliably predict the future. Humans are social animals; we depend on mutual exchange and cooperation in order to survive. And because human personality is fickle and hard to gauge, we are eager to sort the masses into different types of characteristics, so that we can "predict" the behavioural habits and patterns of each kind of person. This is precisely why we have developed all manner of personality-analysis tools — for instance, Astrological Zodiac Personality Traits, the Enneagram, and the Myers-Briggs Type Indicator (MBTI) — and why we so readily "fall for" these tools.

The keys to why personality-analysis tools seem "scarily accurate": the Barnum effect and confirmation bias

The Barnum effect

Why do we believe in these personality-analysis tools so completely? One well-known psychological phenomenon at work is the Barnum effect, which refers to people's tendency to believe that a vague, broadly applicable personality description is a particularly good fit for themselves. Take astrological personality analysis as an example. The following is an excerpt of one website's description of Cancers (this writer happens to be one of these star signs): "…has a very good memory, can be a little emotional, but is extremely attentive to the people they like…. What's more, if a Cancer has nothing particular going on, they would rather hide in their shell all day. …" Let us try a little thought experiment. If I were to change the word "Cancer" in the sentence above to "Virgo," and then hand it to a Virgo to read, how would they react? This writer believes that some people would surely feel the description matched them perfectly — and that is because in anyone's life experience, there are always times when one's "memory" is fairly good, one's mood is rather changeable, or one is lying in bed with nothing to do. In other words, descriptions like these can hardly be called specific or apt.

Confirmation bias

On the other hand, if we already believe in the value of astrological analysis, then when we read these descriptions, we tend to pick out from our lives the instances that fit the astrological description (even highly unusual ones), thereby reinforcing our existing belief all the more — and this is confirmation bias. As a result, round and round it goes, and this kind of "blind faith" in astrological personality analysis becomes ever more unshakeable.

Personality is not a conclusion, but a starting point

Even though scientifically validated personality-assessment tools (such as the Minnesota Multiphasic Personality Inventory, MMPI, and the Big-Five Personality Test) can produce relatively solid and trustworthy personality reports, this writer would still not encourage readers to believe entirely in the contents of an assessment report, and this is because:

1. Personality is not set in stone. The saying "as the child, so the adult" no doubt has some reference value, but your personality will change to some degree as your life experiences unfold;
2. All the personality-assessment tools in the world do no more than sort people into a number of categories, yet our individuality cannot be reflected by any single assessment tool — it is merely a broad label;
3. More importantly, a personality assessment reflects one of the indicators of your behavioural habits, but it should not become a shackle within your life

For instance, thoughts such as "I'm an introvert; I don't really like socialising by nature, so I might as well keep my friendships to a minimum." Dripping water wears away stone; change begins with a single thought. My personal advice is to treat your personality-analysis results as you would a school report card. At the very least, it does not bind your development; rather, it tells you that, through continual trying and learning, your behavioural habits and abilities can all be changed.

Finally, let this writer offer everyone a chance to exercise the grey cells. One of China's Four Great Classics, Dream of the Red Chamber, contains the following account: when Jia Baoyu had just turned one year old, Jia Zheng, wanting to foretell his son's future ambitions and prospects, laid out objects such as brushes, ink, paper, inkstones, gold and treasures, and books, and let Baoyu grab at them. This is commonly known as the "first-birthday grab." But Baoyu reached only for items like rouge and hairpins, and Jia Zheng flew into a rage: "He will grow up to be nothing but a man of wine and women." May I ask: is the "first-birthday grab" a trustworthy psychological-assessment tool? If not, then why not?