Major Study Finds Just 4 Personality Types

A study of more than 1.5 million volunteers found some people are terrible.

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A study of more than 1.5 million volunteers found some people are terrible.

Personality types might sound like the stuff of pop science and time-wasting internet quizzes, but it turns out they could exist after all. That’s according to a new study from Northwestern University in Illinois, which found evidence to suggest “at least four distinct clusters of personality types exist.”

The study was one of the largest of its kind undertaken in recent years, and assessed the personalities of over 1.5 million volunteers.

After sifting through the responses, researchers said they found four clear-cut personality types: reserved, role models, average and self-centered.

The findings challenge much of what we know about personality, according to study co-author and psychology professor William Revelle.

“People have tried to classify personality types since Hippocrates’s time, but previous scientific literature has found that to be nonsense,” he said.

“Now, these data show there are higher densities of certain personality types.”

Revelle himself admitted he was originally skeptical of the notion that most individuals can be easily divided into personality types.

Despite the popularity of personality tests like the Meyers-Briggs Type Indicator, psychologists themselves have long been cautious of the notion that individuals can be neatly divided into such broad character groups.

“I’m going to be very blunt,” Revelle told The Washington Post.

“My first reaction was this is nonsense,” he said.

However, after seeing the data, Revelle became convinced.

“The data came back, and they kept coming up with the same four clusters at higher densities than you’d expect by chance, and you can show by replication that this is statistically unlikely.” Revelle said.

The Four Personality Types

According to the study, most people fit into the “average” personality type. These people are generally agreeable, but aren’t particularly open to new ideas.

The “reserved” personality is similar, but are less open and more “neurotic.” The researchers defined neuroticism as a tendency to “frequently experience negative emotions, such as anger, worry and sadness.”

“They are not particularly extraverted but are somewhat agreeable and conscientious,” the researchers stated.

Meanwhile, role model personalities are “low in neuroticism and high in all the other traits.”

“They are good leaders, dependable and open to new ideas.”

Finally, researchers found some people are simply “self-centered.”

“Self-centered people score very high in extraversion and below average in openness, agreeableness, and conscientiousness,” the researchers explained.

Although the researchers found these four personalities were distinct, they weren’t necessarily permanent. Young males, for example, were found to be overwhelmingly self-centered, while older men tended to be more split between the three other personality types. On the other hand, the researchers found self-centered personalities are “vastly underrepresented” among all women over the age of 15. This suggests personalities change with age, according to lead researchers Luis Amaral.

“This could be a subject of future research,” he suggested.