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Personality and self, Social and behavioural, Cognition and perception

What do your thoughts reveal about you?

A study explores how much of people's personalities are revealed if you tap into their thoughts.

18 June 2008

By Christian Jarrett

Psychologists have spent a great deal of time investigating how much of our personalities we reveal publicly: in the clothes we wear, the arrangement of our offices, the design of our websites. But what if it were possible to tap into someone’s thoughts? How much of their personality would be revealed? Shannon Holleran and Matthias Mehl attempted to find out.

Ninety students spent twenty minutes in private typing into a computer whatever came into their minds, reporting their thoughts, feelings and sensations. They were told their commentaries would be kept private and anonymous, linked only with their scores on a personality test. Nine judges then read these twenty-minute bursts of thought and attempted to rate the personalities of the students who had written them.

The judges rated the students’ personalities with a high degree of accuracy (as compared with the students’ self-ratings), especially for the essays judged to be most private, as opposed to public, in their content. In fact, accuracy of the personality judgements was higher than for comparable studies that have investigated how much personality is revealed in people’s daily activities, their websites or offices.

Accuracy was highest for the Big Five personality dimensions of Agreeableness, Conscientiousness and Emotional Stability, while being somewhat lower for Extraversion and Openness to Experience.

“Empirically, the findings from this study suggest that a person’s private thoughts and feelings provide good information for the accurate judgement of private personality characteristics,” the researchers said.

Of course, this study was awash with methodological issues. Most notably, it is questionable just how open the students were in their 20 minute “stream of thought” essays, despite the promise of anonymity. Would you be prepared to write exactly what came into your head for a psychology experiment?

Further reading

HOLLERAN, S., MEHL, M. (2008). Let me read your mind: Personality judgments based on a person’s natural stream of thought. Journal of Research in Personality, 42(3), 747-754. DOI: 10.1016/j.jrp.2007.07.011