The Psychology
of Profiles
Meet the Big Five, the most-studied model of personality, and HEXACO, a six-factor model from two Canadian researchers. Then weigh the evidence on the Myers-Briggs and the enneagram, and find out why vague profiles feel so true.
- 00First Principlesp.2
- 01The Big Fivep.4
- 02HEXACOp.5
- 03Myers-Briggsp.6
- 04The enneagramp.7
- 05The Barnum effectp.8
- ✦Self-check · Make it · 5 Questions · Side Questp.9
You'll need: a notebook, a pencil, a few horoscopes or quiz results, and a friend or family member to talk with.
Principles
A first principle is a basic truth you can build on. The psychology of profiles rests on four: traits are scales, not boxes, a good test must be checked with evidence, popular doesn’t mean proven and vague statements feel personal.
What do I already know?
What is necessary?
Everything in this module is built from four bricks. Rate yourself on each one, then check the example to see if your rating holds up.
What is the objective?
By the end, you’ll be able to name and explain the Big Five traits, describe what HEXACO adds, summarize what the evidence says about the Myers-Briggs and the enneagram, and explain the Barnum effect and why online quizzes feel so accurate.
- 01Name the Big Five.
- 02Explain honesty-humility.
- 03Give 2 limits of type tests.
- 04Describe the enneagram fairly.
- 05Explain the Barnum effect.
- 06Spot a Barnum statement.
The list on the left is ours. Now make it yours. What do you want out of this?
How much do you know about the psychology of profiles right now? Shade the boxes in pencil. You'll come back at the end (p.9) and shade it again in pen.
Why start this way? When you know what you already have (1), what you need (2) and where you're going (3), you learn faster and you notice the gaps. Every module on the Psychological Profiles Path starts with these same three questions.
The Big Five
Five broad traits, each a scale.
OCEAN
- Openness: curious, imaginative, likes new ideas
- Conscientiousness: organized, careful, plans ahead
- Extraversion: outgoing, energized by people
- Agreeableness: kind, trusting, cooperative
- Neuroticism: tends to worry or feel stressed (the opposite end is emotional stability)
Words, then numbers
Researchers collected thousands of words people use to describe each other (Lens 6), asked people to rate themselves and others, and used statistics to find which words clump together. From the 1960s to the 1980s, different teams kept finding the same five broad clusters.
No good or bad end
Each trait is a scale, and most people are near the middle (Lens 1). High and low both have strengths: lower extraversion can mean you’re good at focusing alone. Big Five scores predict some things modestly, like aspects of school and work, but they don’t decide your future.
- Which Big Five trait do you think describes you best?
- Why is it useful to think of traits as sliders, not boxes?
Spot the five
Pick 3 made-up characters from books or films. Rate each from 1 to 5 on the Big Five. Which trait best explains how each one acts?Which Big Five trait is about being organized and planning ahead?
HEXACO
HEXACO adds honesty-humility.
A sixth factor
In the early 2000s, Kibeom Lee (University of Calgary) and Michael Ashton (Brock University) studied personality words in many languages and proposed six factors: Honesty-humility, Emotionality, eXtraversion, Agreeableness, Conscientiousness and Openness.
What it adds
People high in honesty-humility tend to be sincere, fair and modest, and are less tempted to cheat or show off. Studies suggest this factor helps explain some behaviours, like playing fair in games and money tasks, a bit better than the Big Five alone.
Five or six?
The Big Five and HEXACO mostly overlap. Scientists still debate which works best for which question. That’s normal: a model is a tool to describe people, not a final truth. Both are tested with data, which is what makes them scientific.
- Why might honesty and humility matter in a team or a game?
- Is it OK for scientists to disagree about five or six factors?
Fair play
Think of a board game or sport. Write 3 made-up moments that show high honesty-humility and 3 that show low. How would you measure it fairly in a questionnaire?Which factor does HEXACO add to the Big Five?
The Myers-Briggs
Types split a slider into boxes.
Sixteen types
Katharine Cook Briggs and her daughter Isabel Briggs Myers built the Myers-Briggs Type Indicator (MBTI) in the 1940s, based on Carl Jung’s 1921 book about types. It sorts people into 4 pairs (like E or I), giving 16 four-letter types. Millions take it each year.
The evidence
- Most people score near the middle of each pair, so a small change flips the letter.
- In retest studies, many people (in some studies about half) get a different type within weeks.
- Its four scales overlap with four of the Big Five, minus neuroticism.
Use with care
Many people find MBTI conversations useful for thinking about differences. But researchers widely say it isn’t a strong scientific measure, and the company that publishes it says it shouldn’t be used to choose people for jobs. Treat your four letters as a conversation starter.
- Have you taken a type quiz? Did the result fit you?
- Why could being near the middle make a type flip?
Middle of the pair
On a line from “Introvert” to “Extravert”, mark where you think you are. Ask 3 people to mark you too. How many of you are near the middle?Give one reason researchers criticize type tests.
The enneagram
Popular, but the evidence is limited and mixed.
Nine types
The enneagram draws nine numbered types around a circle (like “the helper” or “the achiever”). Its modern personality version grew in the 1960s and 1970s from the teachings of Oscar Ichazo and the psychiatrist Claudio Naranjo, and it’s popular in workshops and online.
Limited and mixed
There is much less research on the enneagram than on the Big Five. Some studies find its types line up partly with Big Five traits; others find weak reliability. Reviews generally conclude the evidence is limited and mixed, so its claims haven’t been well tested.
Hold it lightly
If a description helps you think about your habits, that can be useful, like a story that makes you think. Problems start when a type is used to judge people, choose teams or explain away behaviour (“I can’t help it, I’m a Type 8”). People are more than a number.
- Why do you think people enjoy type descriptions so much?
- When could using a type to explain behaviour be unfair?
Test the test
Find a free description of the nine types (an adult checks the site). Without telling a friend which is which, read them 3 descriptions. Can they pick their own type? Talk about why or why not.How many types does the enneagram describe?
The Barnum effect
Vague, flattering statements feel personal.
Same profile, everyone
In 1948, psychologist Bertram Forer gave his students a personality test, then handed each a “personal” profile. All the profiles were identical, mostly taken from a horoscope book. Students rated them, on average, 4.26 out of 5 for accuracy.
Why vague feels true
- Statements fit almost anyone: “You have a need for others to like you.”
- They’re flattering, so we want to agree.
- They cover both sides: “Sometimes outgoing, sometimes reserved.”
- We remember hits and forget misses.
Psychologist Paul Meehl named it the Barnum effect in 1956.
The Barnum effect at work
Many online quizzes use friendly, vague, two-sided results, and people choose quizzes they expect to like. Feeling seen isn’t proof. A real test is checked with data: does it give the same result twice, and does it predict anything?
- Why did Forer’s students believe the same profile was about them?
- How could you tell if a quiz result is vague?
Barnum or not?
Write 4 statements that could fit anyone and 4 that could only fit some people. Swap with a friend. Can they tell which are which?What did Forer’s students rate their identical profiles, on average?
Quick self-check
Six questions, covering every stop. Show your thinking. Answers are upside down at the bottom; no peeking till you're done.
1 · Name the Big Five traits.
2 · Which Canadian researchers developed HEXACO?
3 · What does honesty-humility describe?
4 · Why can MBTI types flip on retest?
5 · What does the evidence say about the enneagram?
6 · What is the Barnum effect?
Re-shade your knowledge meter
How much do you know about the psychology of profiles now? Flip back to p.3 and shade the meter again in pen (or shade this one). Did any of the four bricks on p.2 move from "Not yet" to "Got it"?
The Barnum test
Can one profile fit everyone?
1 · Plan
With an adult, run a gentle Barnum demonstration. Willing volunteers answer a harmless 5-question quiz. Everyone gets the same vague, kind profile. They rate its accuracy from 1 to 5. Then reveal the trick and explain it.
- Adult approved
- Volunteers agreed
- Kind, vague profile
- Reveal and explain
2 · My results
| Rating | People |
|---|---|
| 5 | |
| 4 | |
| 3 | |
| 1–2 |
3 · Must-haves
- Mean rating found
- Revealed the same day
- No names kept
- Thanked everyone
4 · What I found
How accurate did people rate the profile? How did they react when they learned everyone got the same one? What will you check next time you take an online quiz?
Only with willing volunteers and an adult. Keep the profile kind and harmless, explain the trick the same day, keep no names, and never use this to embarrass anyone.
5 Questions
I Still Have
This module didn't answer everything. Good. Write 5 new questions it didn't answer, one of each type below. There are no wrong questions, only ones nobody's asked yet.
★ Star the one question you'd most like answered. You'll need it on the next page.
1What I'll find out
Break your big question into 2 or 3 smaller ones you could actually answer.
2Where I'll look
3How I'll share it
Who I'll share it with:
Done by: