“Happiness is the meaning and the purpose of life, the whole aim and end of human existence,” the ancient Greek philosopher Aristotle once said. But how does one reach this goal? According to a new study by researchers from Japan, a person’s happiness may depend on the size of a specific brain region.

Share on Pinterest Researchers found people who were happier had larger gray matter volume in the precuneus region of the brain.

Study leader Dr. Wataru Sato, of Kyoto University in Japan, and colleagues publish their findings in the journal Scientific Reports.

The definition of happiness has been debated for centuries. In recent years, psychologists have suggested that happiness is a combination of life satisfaction and the experience of more positive than negative emotions – collectively deemed “subjective well-being.”

But according to Dr. Sato and his colleagues, the neurological mechanisms behind a person’s happiness were unclear.

“To date, no structural magnetic resonance imaging (MRI) investigation of the construct has been conducted,” they note.

“Identification of the neural substrates underlying subjective happiness may provide a complementary objective measure for this subjective construct and insight into its information-processing mechanism.”