Open-Source Psychometrics Project
This page serves as documentation for the OSPP Enneagram of Personality Scales.
The Enneagram of Personality is a model of personality with nine personality types. The theory has been developed and promoted by many different people and groups over the years, so there are many different strains and traditions of thought and no definitive assessment procedure or test but the basics are generally agreed upon.
In ennegram theory, the reason why personality types exist is that early in life people try different strategies to get their needs met and protect themselves from pain. The strategy that ends up working for them first becomes their go-to, a self-reinforcing habit that constrains their identity and produces a variety of behaviors and internal experiences. The nine types are the different strategies, each revolving around a core want and basic fear.
| Type | Common name | Core Premise |
|---|---|---|
| 1 | "The Reformer" | Wants to be good, right, and ethical
Fears being corrupt or defective |
| 2 | "The Helper" | Wants to be loved and needed Fears being unwanted |
| 3 | "The Achiever" | Wants to be successful and admired Fears being worthless, unremarkable |
| 4 | "The Individualist" | Wants to be unique and true to themselves Fears having no identity or significance |
| 5 | "The Investigator" | Wants to be capable and knowledgeable Fears being incompetent or ineffective |
| 6 | "The Loyalist" | Wants security and support Fears being abandoned and unable to survive |
| 7 | "The Enthusiast" | Wants freedom and happiness Fears being trapped in pain or deprivation |
| 8 | "The Challenger" | Wants to be strong and in control Fears being harmed or controlled by others |
| 9 | "The Peacemaker" | Wants inner stability and harmony Fears conflict and disconnection |
A second essential piece of enneagram theory is the enneagram figure, which is held to show that each type can grow to take on the positive traits of a specific other type when they achive personal growth (integration), or regress to the negative traits of another type under stress (disintegration).
| Type | Integration | Disintegration |
|---|---|---|
| 1 | → 7 | → 4 |
| 2 | → 4 | → 8 |
| 3 | → 6 | → 9 |
| 4 | → 1 | → 2 |
| 5 | → 8 | → 7 |
| 6 | → 9 | → 3 |
| 7 | → 5 | → 1 |
| 8 | → 2 | → 5 |
| 9 | → 3 | → 6 |
All previous Enneagram tests have been developed by their authors generating items based on their intuition and own personal ideas of what the Enneagram types are. That method has the problem that some questions could be poor measures or out of line with other conceptions of the types, and we would never know.
This test was developed with the goal of making scales that had the highest possible agreement with self reported Enneagram type in a sample of people who said they knew a lot about the Enneagram. This is the "criterion-key" approach of scale development, here using self-identified enneagram type as the criterion.
The first alpha version of the test contained 72 items that were generated by the test creator after reading descriptions of the nine types in various different sources. This early version of the test was offered on-line, after users had completed it they were asked if they already thought they knew their Enneagram type, and how much they knew about the Enneagram model of personality.
7,898 survey responses were collected from people who knew their type, had spent at least several hours learning about the Enneagram and were confident in their self type. The table below shows for each item in the test, how users of each self reported type scored relative to the overall average on that item. For example, the 555 people who reported being Type 1 rated the item "I am always thinking about how I could have done something better" 0.3593 points above average. The table is colored red for the type that scores highest on a question, a blue for the type that scores lowest.
| Item | Type 1 (n=555) | Type 2 (n=1125) | Type 3 (n=639) | Type 4 (n=1382) | Type 5 (n=1435) | Type 6 (n=579) | Type 7 (n=603) | Type 8 (n=696) | Type 9 (n=844) |
|---|---|---|---|---|---|---|---|---|---|
| I am always thinking about how I could have done something better. | 0.3593 | 0.0105 | 0.1574 | 0.0738 | 0.1228 | 0.136 | -0.4327 | -0.2333 | -0.265 |
| Part of me criticizes everything I do. | 0.3349 | -0.0796 | -0.1252 | 0.3931 | 0.1447 | 0.3176 | -0.5556 | -0.5339 | -0.2373 |
| I am critical of people who do not take responsibility for their own lives. | 0.4631 | -0.1841 | 0.2149 | -0.2707 | 0.1382 | 0.1013 | -0.0906 | 0.4187 | -0.3421 |
| I often have to redo other peoples work. | 0.5143 | -0.1704 | 0.3262 | -0.1639 | 0.16 | -0.0442 | -0.3111 | 0.293 | -0.322 |
| I keep my belongings in order. | 0.7284 | 0.0755 | 0.3075 | -0.3259 | -0.0583 | 0.1192 | -0.3967 | 0.1874 | -0.1488 |
| I am a perfectionist. | 0.8952 | -0.1563 | 0.1874 | 0.0849 | 0.142 | -0.0418 | -0.5277 | -0.1334 | -0.3614 |
| I pay careful attention to details. | 0.5474 | 0.0146 | 0.171 | -0.1687 | 0.1473 | 0.1504 | -0.5948 | -0.0412 | -0.1438 |
| I have difficulty saying \"no\". | -0.2165 | 0.7538 | -0.1589 | 0.0603 | -0.4316 | 0.2544 | -0.0037 | -0.9618 | 0.5274 |
| I am very accepting and flexible. | -0.6391 | 0.3872 | 0.0363 | -0.0858 | -0.2287 | -0.2453 | 0.5086 | -0.4407 | 0.5475 |
| I sometimes feel as if everything I do is taken for granted. | 0.1034 | 0.2687 | -0.1244 | 0.0628 | -0.0745 | 0.208 | -0.3459 | -0.1392 | -0.0525 |
| People always seem to want to tell me their secrets. | -0.1883 | 0.5004 | -0.0088 | -0.0996 | -0.3387 | -0.0648 | 0.155 | 0.0508 | 0.1191 |
| I get lots of satisfaction from helping others achieve their goals. | 0.0556 | 0.6136 | 0.1834 | -0.2481 | -0.48 | -0.0294 | 0.025 | 0.01 | 0.2112 |
| I like it when people come to me for guidance. | 0.0294 | 0.3715 | 0.1913 | -0.0647 | -0.368 | -0.0757 | 0.0066 | 0.1416 | 0.004 |
| My relationships with others are what my life is about. | -0.255 | 0.8811 | 0.0624 | -0.0108 | -0.9147 | 0.1688 | 0.4195 | -0.1834 | 0.2749 |
| I work hard. | 0.4825 | 0.2332 | 0.4697 | -0.4307 | -0.1718 | -0.0085 | -0.0741 | 0.2947 | -0.1768 |
| I strive for efficiency. | 0.5528 | -0.0993 | 0.5463 | -0.5237 | 0.2014 | 0.058 | -0.1735 | 0.4006 | -0.375 |
| I put work first. | 0.4616 | -0.1242 | 0.7429 | -0.4231 | 0.1533 | 0.0142 | -0.3032 | 0.3431 | -0.38 |
| I hate incompetent people. | 0.5279 | -0.4984 | 0.331 | -0.1908 | 0.3509 | 0.1061 | -0.1976 | 0.5065 | -0.5238 |
| Money is important to my happiness. | 0.0318 | -0.2321 | 0.5364 | -0.0829 | -0.0527 | 0.1685 | 0.0654 | 0.234 | -0.2602 |
| I step forward when a leader is needed. | 0.3493 | 0.1086 | 0.6853 | -0.4592 | -0.3477 | -0.2622 | 0.3623 | 0.9559 | -0.4079 |
| I like to stand out. | -0.3236 | -0.2248 | 0.6705 | 0.3789 | -0.3071 | -0.5717 | 0.5664 | 0.5601 | -0.5817 |
| I really enjoy feeling bitter sweet. | -0.2188 | -0.1992 | -0.1621 | 0.6254 | 0.0623 | -0.1363 | -0.2859 | -0.109 | -0.2014 |
| I cry. | -0.3116 | 0.5188 | -0.2231 | 0.5887 | -0.5802 | 0.2083 | -0.076 | -0.525 | 0.0451 |
| I can be moved by news stories. | -0.0836 | 0.3378 | -0.0846 | 0.2782 | -0.4198 | 0.0217 | 0.0672 | -0.3247 | 0.1145 |
| My intuition is good guide. | 0.0077 | 0.0227 | 0.0666 | 0.1042 | -0.1147 | -0.2632 | 0.0912 | 0.1892 | -0.0976 |
| I daydream about being in love. | -0.3906 | 0.2212 | -0.2479 | 0.7115 | -0.3781 | 0.0139 | -0.0317 | -0.4488 | 0.0219 |
| I can feel overcome with wonder in nature. | -0.2651 | 0.1035 | -0.3377 | 0.3922 | -0.0881 | -0.2446 | 0.169 | -0.4539 | 0.1996 |
| My unique perspective on life helps cheer other people up. | -0.3644 | 0.3377 | 0.2451 | 0.0518 | -0.5239 | -0.342 | 0.6886 | -0.026 | 0.1612 |
| I spend hours alone with my hobbies. | 0.023 | -0.6269 | -0.4649 | 0.5087 | 0.7111 | -0.1829 | -0.5018 | -0.3366 | -0.0804 |
| I spend so much time planning I run out of energy for the doing. | -0.0279 | -0.092 | -0.195 | 0.2023 | 0.2706 | 0.2308 | -0.2625 | -0.5025 | -0.0602 |
| I am curious about everything. | -0.1586 | -0.2407 | -0.1144 | 0.075 | 0.3353 | -0.3026 | 0.3045 | 0.0045 | -0.1755 |
| I must always be having new experiences. | -0.431 | -0.1496 | 0.3615 | 0.1436 | -0.238 | -0.4883 | 1.0477 | 0.3395 | -0.3572 |
| I have a hard time showing emotions. | 0.1409 | -0.7163 | -0.1032 | -0.3413 | 0.9649 | 0.0001 | -0.3999 | 0.1865 | 0.0038 |
| I spend most of my time trying to understand things. | -0.0986 | -0.3227 | -0.2668 | 0.2318 | 0.6235 | -0.1398 | -0.2357 | -0.2967 | -0.2242 |
| I try and hide the fact that I am sensitive. | 0.0445 | -0.3145 | -0.1039 | 0.0558 | 0.3713 | 0.1129 | -0.184 | -0.0936 | -0.0823 |
| I am loyal. | 0.0868 | 0.2569 | -0.0841 | -0.1419 | -0.1645 | 0.2665 | -0.1003 | 0.0317 | 0.0462 |
| I put family first. | 0.0829 | 0.5766 | 0.0725 | -0.2552 | -0.458 | 0.2518 | -0.0056 | -0.0861 | 0.2111 |
| I am annoyed by how most people are not as responsible as me. | 0.7076 | -0.0691 | 0.348 | -0.3446 | 0.1297 | 0.216 | -0.472 | 0.4002 | -0.4273 |
| I get input from others before I make a decision. | -0.1047 | 0.3361 | 0.0909 | -0.0642 | -0.3105 | 0.4078 | 0.0204 | -0.3759 | 0.2022 |
| I prefer it when leaders are decisive. | 0.2342 | -0.094 | 0.2181 | -0.2754 | -0.0124 | 0.1716 | -0.0435 | 0.3754 | -0.107 |
| It is good to wake up to a full day of planned activities. | 0.278 | 0.0944 | 0.5516 | -0.324 | -0.1789 | -0.0241 | 0.1473 | 0.2919 | -0.2603 |
| I'd take a stiff jail sentence over ratting on a friend. | -0.1661 | 0.0909 | -0.1549 | 0.0673 | -0.0916 | 0.04 | 0.0241 | 0.1414 | 0.0228 |
| I always try to break the tension with a good joke. | -0.3084 | 0.1008 | 0.1975 | -0.1754 | -0.2949 | -0.0166 | 0.7245 | 0.0992 | 0.1502 |
| I can keep a conversation going with anyone about anything. | -0.2364 | 0.4986 | 0.5357 | -0.3457 | -0.6571 | -0.2974 | 0.9184 | 0.52 | -0.133 |
| I can see a use for most things people think are junk. | -0.2235 | -0.0868 | -0.1373 | 0.1088 | 0.1859 | -0.1941 | 0.1597 | -0.0003 | -0.1033 |
| I like mental challenges. | 0.1105 | -0.2915 | 0.145 | -0.188 | 0.4297 | -0.2487 | 0.0094 | 0.2877 | -0.2615 |
| I do not like it when people expect me to be great, even if I want to be. | -0.2235 | -0.1641 | -0.534 | 0.3049 | 0.2754 | 0.3188 | -0.2118 | -0.5931 | 0.2142 |
| I am uninhibited. | -0.3162 | -0.0179 | 0.2036 | -0.037 | -0.2422 | -0.3926 | 0.7659 | 0.5743 | -0.1994 |
| I love to travel. | -0.123 | 0.0728 | 0.1539 | 0.0647 | -0.2745 | -0.2291 | 0.4609 | 0.1418 | -0.0487 |
| I know what is right and what is wrong. | 0.3243 | 0.1575 | 0.0869 | -0.1397 | -0.1692 | 0.0321 | -0.1556 | 0.1538 | -0.0037 |
| Fear of being taken advantage of keeps me from being more trusting. | -0.0297 | -0.3387 | -0.2066 | 0.074 | 0.3951 | 0.46 | -0.4076 | 0.1762 | -0.3167 |
| I want people to tell me the truth, not spare my feelings. | 0.1266 | -0.2163 | 0.0356 | -0.2133 | 0.293 | -0.1202 | 0.0159 | 0.4657 | -0.2915 |
| I naturally emerge as a leader. | 0.3938 | 0.0694 | 0.8206 | -0.5371 | -0.3498 | -0.4119 | 0.417 | 1.1928 | -0.5053 |
| I like a conversation where no one agrees. | -0.1609 | -0.3908 | 0.0728 | -0.0172 | 0.3998 | -0.3441 | 0.2187 | 0.5128 | -0.4084 |
| I side with the rebels over the establishment. | -0.3737 | -0.3818 | -0.3196 | 0.4608 | 0.1831 | -0.308 | 0.3361 | 0.2452 | -0.244 |
| I do not conform. | -0.1857 | -0.4048 | -0.2208 | 0.3826 | 0.2835 | -0.4615 | 0.2614 | 0.3918 | -0.4318 |
| When other people are arguing, I leave the room. | -0.1611 | 0.1072 | -0.3415 | 0.1956 | 0.0814 | 0.1507 | -0.2274 | -0.9105 | 0.6021 |
| I can have difficulty making choices, all options just seem so good. | -0.6524 | 0.1192 | -0.3808 | 0.2372 | -0.0355 | 0.2388 | 0.4421 | -0.8515 | 0.4337 |
| I want to feel one with nature. | -0.2736 | 0.1154 | -0.3419 | 0.343 | -0.106 | -0.2495 | 0.1558 | -0.4207 | 0.2739 |
| I avoid confrontation. | -0.2752 | 0.2479 | -0.3848 | 0.2141 | 0.0547 | 0.2864 | -0.2896 | -1.3399 | 0.8464 |
| I like listening to people talk about their problems. | -0.2281 | 0.5909 | -0.1539 | 0.1579 | -0.4459 | 0.0191 | -0.0419 | -0.2734 | 0.2224 |
| I keep my thoughts to myself, to prevent trouble. | -0.1378 | -0.0738 | -0.3754 | 0.1218 | 0.4057 | 0.1947 | -0.5724 | -0.8782 | 0.5811 |
| I hate war. | -0.0538 | 0.2041 | -0.2257 | 0.2431 | -0.1456 | 0.0388 | 0.0825 | -0.7149 | 0.3079 |
In 2021 Kayleigh Kastelein, an undergraduate student at Olivet Nazarene University published an analysis of the OEPS (Kastelein, 2021) as her honors thesis. Her conclusion was that "overall, this study showed OEPS did not show strong reliability or validity evidence." Which I generally agree with, the OEPS is not a great psychometric measure by academic standards. And I think her study was well constructed. However, for the purpose that it was created, I do think the OEPS is still reasonable. That purpose being: predicting Ennegram type in individuals with known type and recommending individuals who are not familair with the Ennegram a type they would be able to identify as.
One weakness that she identified that I do think should be addressed was modest test-retest reliability (in her sample: 0.68 for the OEPS compared to 0.85 for the BFI). This mostly means increasing the number of items, with only 4 items per type, the OEPS is a short instrument for sure.
In 2026, a expansion of the OEPS was undertaken when a new dataset was completed that seemed like it could be used to key more items for the 9 Enneagram types. The datset is from the Statistical "Which Character" Personality Quiz where participants answered some of a bank of 500 items and could also report their self identified personality types. This set of 500 items is a much larger item set than was evaluated in the first round of development, but on the other hand was less tailored towards items that might key for a Ennegram type. The sample size is very large, with 170,857 in total identifying their type. Each person saw only a minority of the possible items however, so effective sample size averaged 22,709 people per item (range: 103,878 - 783). These aggregate statistics are in the file SWCPQ-items-by-ennegram-type.ods. The file shows on each row, the item and average scores for each type (with type sample size). Sample sizes for some items were low (e.g. 783) but the items with low sample sizes were mostly given to fewer users because they were excluded on a rational basis in the development of the SWCPQ (were more meaningless), so sample sizes for items that correlated with ennegram types happen to be larger thankfully.
Instead of keying 1 item to 1 type as in the v1 set, for this next round of items I wanted them to multi-key. This is where, for example the response to an item could add to the scale for one type but also at the same time subtract from the scale for a different type. I like having multi-keyed items for user experince because it increases item diversity (repetitive items are boring). It does mean people doing statistics on scale scores do need to be careful (because correlation between scale scores is dramatically inflated by direct inclusion of correlated error), but given the topic of this test making an instrument optimized towards research purposes does not seem to be the highest priority.
Some facts observations about the situation also seem to make multi-keying kind of make sense. In the v1 item screening, it appears that many of the types load on multiple items and that some of the types are kind of mirrors of each other (e.g. the correlation between average scores per item between Type 8 and Type 9 was r=-0.81 in the v1 sample). Also, the items from the SWCPQ are in the form of bipolar adjective pairs, which makes their orientation arbitrary and is explicitly a contrast between two different possibilities. So the idea of trying to multi key each item towards two different types seemed appealing. To make it balanced, a set of 9 items each keying towards two of the types (with each type being keyed twice) was desired. Such as set does not necessarily have to exist, but something like it was successfully found! A script search the data table and found the below set of items. This table shows the items selected, and the average score of each type after mean centering.
| Item | Type 1 avg | Type 2 avg | Type 3 avg | Type 4 avg | Type 5 avg | Type 6 avg | Type 7 avg | Type 8 avg | Type 9 avg | Sample size |
|---|---|---|---|---|---|---|---|---|---|---|
| 41 : rational <-> whimsical | -11.0 | 7.0 | -3.1 | 10.7 | -9.4 | -3.1 | 10.0 | -4.7 | 3.6 | 37197 |
| 62 : confident <-> insecure | -2.6 | 4.2 | -7.6 | 8.4 | 4.3 | 12.1 | -11.2 | -18.5 | 10.8 | 38357 |
| 72 : extrovert <-> introvert | 5.5 | -6.1 | -12.7 | 7.3 | 19.6 | 11.6 | -23.3 | -13.6 | 11.7 | 37674 |
| 15 : orderly <-> chaotic | -14.6 | -1.5 | -4.3 | 8.0 | -0.4 | -3.3 | 13.1 | 4.9 | -1.9 | 97945 |
| 136 : unambitious <-> driven | 7.2 | 1.2 | 12.5 | -5.0 | -4.5 | -4.5 | -0.2 | 8.8 | -15.5 | 26138 |
| 166 : wild <-> tame | 6.2 | 2.8 | -1.4 | -3.1 | 2.9 | 6.4 | -12.5 | -12.2 | 11.0 | 70041 |
| 397 : touchy-feely <-> distant | 3.2 | -17.3 | -1.5 | -3.2 | 18.0 | 2.9 | -6.5 | 5.7 | -1.4 | 25657 |
| 400 : never cries <-> often crying | -2.0 | 13.3 | -1.7 | 12.5 | -12.9 | 3.9 | -2.5 | -14.5 | 3.9 | 37302 |
| 444 : harsh <-> gentle | -0.3 | 14.1 | -4.9 | 2.1 | -7.3 | 0.3 | -2.6 | -15.7 | 14.4 | 7682 |
For example, you can see that Type 1's rated them selves 16.1 points more self-disciplined (vs. disorganized) on a 1 - 100 scale than average. The two types each item should key for are highlighted in yellow, differences > 0 favor the 2nd option of the item. A cut off of a +/-10 point difference from average was used to make an item eligible to key for a type.
There was not a second set of 9 items that could form a valid multi-key, so 9 more items were select just to key for a single type. These are in the table below.
| Item (low <-> high) | Type 1 avg | Type 2 avg | Type 3 avg | Type 4 avg | Type 5 avg | Type 6 avg | Type 7 avg | Type 8 avg | Type 9 avg | Sample size |
|---|---|---|---|---|---|---|---|---|---|---|
| 75 : disorganized <-> self-disciplined | 16.1 | -0.3 | 8.7 | -9.3 | -0.5 | -0.2 | -11.7 | 3.2 | -6.1 | 29,049 |
| 179 : poisonous <-> nurturing | 0.8 | 14.4 | -1.4 | 0.3 | -10.3 | 0.9 | -1.0 | -10.9 | 7.4 | 7,4672 |
| 486 : social climber <-> nonconformist | -0.9 | -3.4 | -12.9 | 7.8 | 7.8 | 2.4 | -3.8 | 0.4 | 2.6 | 7,406 |
| 499 : stable <-> unstable | -9.6 | -2.7 | -4.7 | 11.2 | 1.7 | 4.5 | 2.6 | 0.3 | -3.3 | 7,686 |
| 452 : people-person <-> things-person | 4.4 | -12.9 | -4.6 | 3.4 | 17.9 | 6.7 | -12.0 | -2.9 | -0.1 | 7,542 |
| 494 : hopeful <-> fearful | -3.0 | -4.6 | -3.6 | 5.2 | 7.5 | 11.9 | -9.5 | -3.5 | -0.5 | 7,623 |
| 47 : spontaneous <-> deliberate | 9.6 | -1.1 | 2.2 | -3.9 | 6.4 | 6.9 | -16.9 | -4.2 | 1.0 | 45,586 |
| 141 : thick-skinned <-> sensitive | -0.3 | 11.8 | -2.6 | 11.1 | -8.8 | 5.5 | -6.1 | -18.5 | 7.9 | 27,524 |
| 357 : neutral <-> opinionated | -0.6 | 0.4 | 3.3 | 3.7 | -3.1 | -1.8 | 2.4 | 9.6 | -13.9 | 34,031 |
With the original OEPS and these 18 new items, the OEPS2 has 54 items and can be downloaded as OSPP-Enneagram-of-Personality-Scales-v2.odt.