Big Five versus type models
Two ways of describing personality: as positions on continuous traits, or as membership of a type. The choice changes what scores can and cannot tell you.
Traits versus types
| Trait models (for example the Big Five) | Type models (for example the MBTI) | |
|---|---|---|
| What a result is | A position on each of several continuous dimensions | A category, such as one of 16 types |
| How scores are built | Scale scores, often compared with a norm group | Scale scores split at a cut-point into one pole or the other |
| Near the middle | A middle score is reported as middle | A small change can flip the type |
What research found
A 1989 study found that the MBTI's four scales relate to four of the five factors of the Big Five (McCrae and Costa, 1989). Later work found little support for the sharp boundaries between types that a type model implies (Bess and Harvey, 2002). Trait measures such as the Big Five have the broader research base.
Why cut-points matter
Every score contains some measurement error. When a continuous score is split into two categories, people close to the cut-point can land on either side from one sitting to the next, even if nothing about them has changed. Trait reports avoid this by keeping the score continuous.
What each is used for
- Research: trait models dominate, because continuous scores suit statistical analysis.
- Development and team work: both are common; types are easy to remember, traits are more precise.
- Selection: any instrument needs evidence for that specific use, and safeguards. See personality tests in hiring.
Questions to ask before choosing
- Is the result continuous or a category?
- What evidence supports the use you have in mind?
- Are scores compared with other people or only within the person?
- How stable are results on retest?
Where the ICA sits
The ICA reports four dimension scores and a profile that orders them from strongest to weakest; a profile is an ordering, not a type. It is a forced-choice instrument, so its scores describe one person's own preferences; see forced-choice and ipsative scoring. Its accuracy is currently being studied.
Questions
Is the MBTI a Big Five test?
No. They are different instruments built on different models, although research has found that their scales overlap.
Sources
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Big Five traits versus type models such as the MBTI: how scores are built, what research found, what each suits, and what to ask before choosing.