Do personality tests work? - Merve Emre
In 1942, a mother-daughter duo
Katherine Cook Briggs
and Isabel Briggs Myers
developed a questionnaire that classified
people’s personalities into 16 types.
Called the Myers-Briggs Type Indicator,
or MBTI,
it would go on to become
one of the world’s
most widely-used personality tests.
Today, personality testing
is a multi-billion dollar industry
used by individuals, schools,
and companies.
But none of these tests, including
the MBTI, the Big Five,
the DiSC assessment,
the Process Communication Model,
and the Enneagram,
actually reveal truths about personality.
In fact, it’s up for debate
whether personality
is a stable, measurable feature
of an individual at all.
Part of the problem is the way the tests
are constructed.
Each is based on a different set
of metrics to define personality:
the Myers-Briggs, for instance,
focuses on features like introversion
and extroversion
to classify people into
personality "types,"
while the Big Five scores participants
on five different traits.
Most are self-reported,
meaning the results are based on questions
participants answer about themselves.
So it’s easy to lie, but even with
the best intentions,
objective self-evaluation is tricky.
Take this question from the Big Five:
How would you rate the accuracy
of the statement "I am always prepared"?
There’s a clear favorable answer here,
which makes it difficult to be objective.
People subconsciously aim to please:
when asked to agree or disagree,
we show a bias
toward answering however we believe
the person or institution
asking the question wants us to answer.
Here’s another question—
what do you value more,
justice or fairness?
What about harmony or forgiveness?
You may well value both sides
of each pair,
but the MBTI would force
you to choose one.
And while it’s tempting to assume
the results of that forced choice
must somehow reveal a true preference,
they don’t:
When faced with the same forced choice
question multiple times,
the same person will sometimes
change their answer.
Given these design flaws, it’s no surprise
that test results can be inconsistent.
One study found that nearly half of people
who take the Myers-Briggs a second time
only five weeks after the first
get assigned a different type.
And other studies on the Myers-Briggs have
found that people with very similar scores
end up being placed
in different categories,
suggesting that the strict divisions
between personality types
don’t reflect real-life nuances.
Complicating matters further,
the definitions of personality traits
are constantly shifting.
The Swiss psychiatrist Carl Jung,
who popularized the terms
introvert and extrovert,
defined an introvert as someone who sticks
to their principles
regardless of situation,
and an extrovert as someone who molds
their self according to circumstance.
Introversion later came to mean shyness,
while an extrovert was someone outgoing.
Today, an introvert is someone who finds
alone time restorative,
an extrovert draws energy
from social interaction,
and an ambivert falls somewhere
between these two extremes.
The notion of an innate,
unchanging personality
forms the basis of all these tests.
But research increasingly suggests that
personality shifts during key periods—
like our school years,
or when we start working.
Though certain features
of a person’s behavior
may remain relatively stable over time,
others are malleable, moulded by our
upbringing, life experiences, and age.
All of this matters more or less depending
on how a personality test is used.
Though anyone using them should take
the results with a grain of salt,
there isn’t much harm in individual use—
and users may even learn some
new terms and concepts in the process.
But the use of personality tests extends
far beyond self discovery.
Schools use them to advise students
what to study and what jobs to pursue.
Companies use them decide who to hire
and for what positions.
Yet the results don’t predict how a person
will perform in a specific role.
So by using personality tests this way,
institutions can deprive people
of opportunities they’d excel at,
or discourage them from considering
certain paths.
