Japanese scientists say they've found the key that determines how happy you are

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Photo: Shuttershock

Julian Ryall

If you're happy and you know it, it's because you have an enlarged precuneus.

A team of Japanese scientists has determined that the amount of grey matter within the precuneus - a portion of the brain at the upper rear of the right cerebral hemisphere - determines how happy a person is.

In a study published in the British academic journal Scientific Reports, researchers from Kyoto University and Shiga University said they used magnetic resonance imaging to measure the size of different parts of the brains of a control group of 51 students aged between their teenage years and their late 30s.

The scans were then compared with the results of a written survey in which the test subjects were asked to measure their subjective happiness on a scale of one to seven, the intensity of their positive and negative emotional experiences and their purpose in life.

"We found a positive relationship between the subjective happiness score and grey matter volume in the right precuneus," Wataru Sato, an associate professor of neurology in Kyoto University's Graduate School of Medicine, wrote in the study.

Examination of other parts of the brain showed no correlation with the happiness of the test subjects.

"Moreover, the same region showed an association with the combined positive and negative emotional intensity and purpose in life scores," Professor Sato added. "Our findings suggest the precuneus mediates subjective happiness by integrating the emotional and cognitive components of happiness."

The precuneus is known to be the part of the brain closely connected to emotions and the scientists' latest discovery suggests that it serves to bring together feelings and thoughts to provide the sense of happiness.

It is also believed that the precuneus can temporarily contract or expand according to a person's state of mind.

Professor Sato and his team intend to continue their research and answer philosophical questions, such as those posed by Aristotle about the meaning of happiness and the goal of human life.