Personality type tests are hugely popular, though if you ask working psychologists, they’ll tell you the results are little better than astrological signs. But a new study, based on huge sets of personality data representing 1.5 million people, has persuaded one of the staunchest critics of personality types to conclude that maybe distinct types exist, after all.

In a report published Monday in the journal Nature Human Behavior, researchers at Northwestern University in Illinois identify four personality types: reserved, role models, average and self-centered.

The new approach was nothing like the basis for widely used personality tests such as the Myers-Briggs, which spits out a personality type with acronyms like INTJ, for introversion-intuition-thinking-judgment, or ESFP (that’s extrovert-sensing-feeling-perceiving).

“The social psychology community is pretty in line with being anti Myers-Briggs Type personality assessments,” said Alexander Swan, a psychologist at Eureka College in Illinois who is a critic of the test.

That test, developed in the 1940s, is based on Swiss psychoanalyst Carl Jung’s idea that people can be grouped into archetypes. (These archetypes weren’t empirical findings, just Jung’s assessment of literary motifs and his observations of the people he knew.) Myers-Briggs tests generate one of 16 archetypes for each user, but the questions are poorly written, Swan said. And several studies show that the personality types are inconsistent and cannot predict career success or other characteristics.

People have been trying to stuff each other into categorical bins for thousands of years. “These ideas go back to the ancient Greeks like Hippocrates and so on,” said Martin Gerlach, a postdoctoral researcher who studies complex systems at Northwestern University.

Gerlach and his colleagues Luís A. Nunes Amaral and Beatrice Farb are trying to propel these old ideas into the realm of big data. They took a relatively new approach — not adhering to Jungian theories but analyzing four huge data sets.

They also enlisted the aid of Northwestern psychologist William Revelle, who had been an outspoken skeptic of the idea of personality types. He was, at first, a critic of the group’s own study. “I’m going to be very blunt,” he said. “My first reaction was this is nonsense.”

Social psychologists dispute whether personality types exist. Traits are another matter. Personality traits “can be measured consistently across ages, across cultures,” said Amaral, co-director of the Northwestern Institute on Complex Systems. The five best-established traits, or Big Five, are openness, conscientiousness, extroversion, agreeableness and neuroticism.

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