personality type
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We’re often told that we’re unique and that no two people are exactly alike. But researchers at Northwestern University have been able to group 1.5 million study participants into four simple personality-based categories. In their study, published on September 17th in The Journal Nature Human Behavior, researchers also found that over time, people can shift from one category to another.

Previous personality categorization studies have been based on smaller groups of participants. Revelle wanted to expand his study to a wider participant-base to prove that personality types are not only valid, but are based in science—not just self-help literature. The below personality types were extracted and organized based on online questionnaires developed over several decades.

So which personality type are you?


The first personality type is called “average” (but don’t worry—that doesn’t mean the people who get this type are average…it just means that the majority of participants were this type). Those who fall into the average category are extroverted and “neurotic.” Women are more likely to be this type than men, and while extroverted, average people are often fairly closed-off in terms of their emotions.


Those in the “reserved” category are less extroverted, and more agreeable and emotionally stable. Like the respondents in the average category, reserved people are not usually too open with their feelings. The authors stated that gender and age does not really factor into a reserved personality type.


On the opposite side of the spectrum, “self-centered” people are extremely extroverted yet aren’t very agreeable. “These are people you don’t want to hang out with,” Revelle said. Self-centered types are usually young, and (thankfully) people tend to become less of this type as they age.

Role Model

Finally, those in the “role model” category are extroverted, open to others, very agreeable, conscientious, and not neurotic. Older adults tend to embody the role model personality (older women, specifically). They’re also often dependable and open-minded.

This new study merely scratches the surface of scientific research into personality types and categories. But with this being one of the largest studies out there, future researchers can use these findings to launch more in-depth studies. Which personality type best fits you?