Being 'Even-Tempered' Can Lead to Better Health Outcomes.

Women outlive men by an average of 4–6 years globally, a gap observed in nearly every country in the world. In Japan, average female life expectancy exceeds 87 years. Scientists point to biological factors including two X chromosomes (which may buffer genetic defects), higher estrogen levels that protect cardiovascular health, and lower rates of risk-taking behavior. Social factors such as lower rates of smoking and alcohol consumption also contribute.

Japan consistently leads the world in longevity. As of the early 2020s, Japan had over 90,000 centenarians — people aged 100 or older. Women outnumber men by about six to one among centenarians. Factors include diet (especially in Okinawa), strong social bonds, universal healthcare, and cultural attitudes toward aging.

The gut-brain axis directly links emotions to digestion. Stress and anxiety can slow or disrupt the digestive process, making indigestion one of the most common physical symptoms of mental stress.

Multiple controlled studies show that regularly writing down three things you are grateful for — for as little as three weeks — significantly increases life satisfaction, reduces depressive symptoms, and improves sleep quality. Gratitude activates the brain's reward circuits and increases dopamine and serotonin production. A landmark 2005 study by Martin Seligman found that a 'gratitude visit' — writing and personally delivering a thank-you letter — produced the largest increase in happiness of any positive psychology intervention tested.