Incredible facts
A new study suggests that human faces carry more information for socially active people than for those who are more introverted. The results show that extroverts pay more attention to people's faces than introverts do. In fact, as it turns out, an introvert's brain makes no distinction between inanimate objects and human faces.
The results partly explain why extroverts are more likely to seek out the company of others than introverts, or why shy people prefer to hang out with a good book than with a group of friends. The study also reinforces the idea that neural differences in a person's brain determine their personality.
“We have just received further evidence that personality is more than just a psychology concept,” says lead researcher Inna Fishman from the Institute of Biological Sciences sciences in La Jolla, CA. “There is a broader basis for visible human behavior, with different types of personality corresponding to different neural bases.”
Personality in the brain
There are many ways to describe a person's character, from talkative and restless to work-loving and organized. Psychologists have found that many traits often go hand in hand, so they've grouped them into five main overarching categories — extroversion, neuroticism, openness to experience, collaboration, good faith.
Extraversion has to do with how a person interacts with other people. Extroverts like to be in the company of others and generally enjoy their social environment, while introverts are quite different. Previous research has also shown that extroverts tend to be more assertive, they are more likely to experience positive emotions, and are generally more satisfied with their lives.
However, there has never been a study investigating whether extroverts are more sensitive to “stimuli” in social situations, such as faces. To find out, Fishman and her colleagues recruited 28 people aged 18 to 40 to participate in the experiment and divided them into groups — introverts, transitions, and extroverts. At the same time, each participant's brain activity was recorded by electrodes placed on their heads, that is, a technique known as electroencephalography (EEG) was used.
The researchers observed specific changes in the brain's electrical activity, known as P300. These changes are usually in the form of deviations in the EEG, which can be caused, for example, by changes in the environment, for example, when the room is very quiet, and suddenly someone suddenly sneezes. The brain reacts 300 milliseconds before a person realizes the changes that have taken place.
To induce the P300 effect, Fishman used a technique known as the “strange task”, in which subjects see a series of very similar images, such as a group of blue cars, and then, suddenly an image appears that is completely different from those seen before, such as a red car.
In the current experiment, participants were shown a series of male faces, sometimes including women. They were also shown photos of purple flowers, among which yellow flowers appeared from time to time.
Faces or flowers?
The more points a person scored on the extroversion test, the stronger their P300 response to human faces. In other words, extroverts pay more attention to human faces (P300 can be seen as an indicator of human attention, or how quickly the brain reacts to changes).
No relationship was found between the P300 response and flower images among extroverts. As for introverts, in this case, the P300's response to both flowers and human faces was the same. “They just don't give much importance to social stimuli, meaning human faces are just as much of a stimulus as any other (in this case, flowers),” Fishman says.
“This supports the claim that introverts, or their brains, can be indifferent to people, accept them or leave them behind. An introvert's brain evaluates interactions with others as if it's in contact with other non-human information, such as inanimate objects,” Fishman continues.
The results strongly suggest that human faces, and people in general, matter much more to extroverts.