The idea of personality types first appeared sometime between 460 and 370 BC in the work of Hippocrates.

Hippocrates theorised that personality traits are based on the four temperaments associated with four fluids of the body: choleric temperament (yellow bile from the liver), melancholic temperament (black bile from the kidneys), sanguine temperament (red blood from the heart), and phlegmatic temperament (white phlegm from the lungs).

All of which is disgusting and not true, thank the gods.

Since then, the idea of definitive personality traits has largely been the domain of pop-psychology and self-help books, until now.

Here’s The Telegraph:

Researchers at Northwestern University in Illinois sifted through data from more than 1.5 million questionnaire respondents and found at least four distinct clusters of personality types exist: average, reserved, self-centered and role model.

This is the first time that personality types have made it into a scientific journal. The accuracy of the data sets was due in part to the size of the study sample.

The new study used answers from four online questionnaires including the BBC Big Personality Test.

“The thing that is really, really cool is that a study with a dataset this large would not have been possible before the web,” added Dr Amaral.

“Previously, maybe researchers would recruit undergraduates on campus, and maybe get a few hundred people. Now, we have all these online resources available, and now data is being shared.”

From those datasets, the team plotted the five widely accepted basic personality traits: neuroticism, extraversion, openness, agreeableness and conscientiousness.

Without further ado, here are the four definitive personality types:

Average

Average people are high in neuroticism and extraversion, while low in openness.

“I would expect that the typical person would be in this cluster,” said Martin Gerlach, a postdoctoral fellow in Amaral’s lab and the paper’s first author. Females are more likely than males to fall into the Average type.

Reserved

The Reserved type is emotionally stable, but not open or neurotic. They are not particularly extroverted, but are somewhat agreeable and conscientious.

Role Models

Role Models score low in neuroticism and high in all the other traits.  The likelihood that someone is a role model increases dramatically with age.

“These are people who are dependable and open to new ideas,” Amaral said. “These are good people to be in charge of things. In fact, life is easier if you have more dealings with role models.”  More women than men are likely to be role models.

Self-centred

Self-centred people score very high in extraversion and below average in openness, agreeableness and conscientiousness.

“These are people you don’t want to hang out with,” Revelle said. There is a very dramatic decrease in the number of self-centred types as people age, both with women and men.

Which of the four types are you, then?

Before you start scrutinising your teenager, trying to figure out if they’re going to be self-centred forever, there’s some good news. Personality isn’t fixed, but changes as we grow and evolve.

Try not to spend the rest of the day categorising your friends and coworkers.

[source:telegraph]