With March 20 declared International Happiness Day -- a day to celebrate the importance of happiness in our lives and the world, it's an occasion to pose the question, "Can we tell people are truly happy just from their laugh?"
In a small study, Dr. Carolyn McGettigan, a Department of Psychology professor at the Royal Holloway, University of London, found that the brain responds differently to fake and real laughter. Her work examined brain responses of 58 participants who listened to people laugh as they watched funny YouTube videos, which resulted in real laughter. The participants also listened to forced laughter from the same people. The participants weren't informed the study was about laughter perception, and "demonstrated different neurological responses when they heard false laughter."
The study suggests our brains know the difference between real and fake laughter, and attempt to "work out" what makes the fake laughter just that.
"As we celebrate International Day of Happiness today, it's fascinating to consider the way our brain is able to detect genuine happiness in other people," said Dr. McGettigan. "Our brains are very sensitive to the social and emotional significance of laughter.
"During our study, when participants heard a laugh that was posed, they activated regions of the brain associated with mentalizing in an attempt to understand the other person's emotional and mental state.
"Indeed, some of the participants engaged parts of the brain that control movements and detect sensation. These individuals were more accurate at telling which of the laughs were posed, and which were real. This suggests that as listeners, 'trying out' how a laugh would feel if we produced it ourselves might be a useful mechanism for understanding its meaning."
Previous research cited in the current study investigated how the brain perceives humour, with "the right frontal cortex, the medial ventral prefrontal cortex, the right and left posterior (middle and inferior) temporal regions and possibly the cerebellum" appearing to be involved to "varying degrees."
Meanwhile laughter's ability to release endorphins has also been investigated for being able to alleviate pain; that study, published in 2011 in Royal Society B, also found a distinction between genuine and forced laughter, with genuine laughter in a social context having a noticeable effect.
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