When it comes to psychological tests, they need to be reliable in order to be accurate. We again use reliability in a nerdy way: the test itself demonstrates a similar result when repeated over time, between individuals, or in other ways. The Enneagram is a popular test of personality, but how do assessment experts view it? Is the Enneagram reliable? And what does that mean for valid results?
The Enneagram consists of nine proposed personality types. A mid-20th century Bolivian philosopher developed these mysticism-influenced types. The test determines personality type(s) by having the individual identify primary types they relate with or by giving them structured surveys.
Many settings, from counseling practices to business organizations, use the test. So it has done well in a marketing sense, but is the Enneagram reliable? Research finds the test has questionnable reliability and validity. Therefore, it is not approved by most testing experts.
This is for a few reasons. First, the nine categories were created by reasoned explanations and were not tested psychometrically. Psychometric testing is an important step in developing psychological tests because it examines how test items relate to validated psychological concepts and to other related validated tests.
Second, research conducted on the existing Enneagram test finds mixed results, at best. Importantly, the test does not demonstrate reliability across studies. That is, it does not consistently generate similar scores over time or across individuals. So you could give it to the same person multiple times or across groups of people and it’s scores will not stay relatively consistent.
The need to replicate results consistently is important for ensuring we know that a test measures what it says it measures. This is a test’s validity. When a test claims to measure a certain “thing” or phenomenon, it should pick up on the presence of that thing in the same way each time it measures it. Otherwise, it could be measuring something completely different than it claims to measure.
So if the Enneagram is reliable also affects whether it is valid. Unfortunately, the Enneagram does not appear to do so. The Myer’s Briggs personality test demonstrates similar concerns for reliability and validity.
This is why we often tell people to take many online survey tests “with a grain of salt.” The lack of known reliability or validity means one should not take the results as “gospel” or get clinical or diagnostic utility from them.
Other, professionally sought-after personality tests do show high reliability and validity. The Minnesota Multiphasic Personality Inventory (now in its 3rd version, MMPI-3) and the Personality Assessment Inventory (PAI) both do so. They also both map on to clinical concepts well. Both tests require some training to understand, but also have online services that help analyze and explain results.
The Enneagram is a popular and theoretically-appealing measure of personality. But popularity and appeal does not mean a measure is helpful (even if people like it). Luckily there are reliable and valid tests out there that can help therapists more deeply understand clients and their difficulties so they can help.
