Happier Japanese adults live longer, a new study published in 2016 found. health psychologyThey found that people who described themselves as unhappy had a significantly higher risk of death over a seven-year period.
Happiness has long been linked to improved health, but most of the evidence comes from Western countries. Researchers wonder if the same pattern holds true in cultures where emotional expression is more restrained and definitions of happiness are different. In Japan, for example, happiness is more often associated with calmness and social harmony than with excitement and personal accomplishment. In this context, understanding whether happiness predicts longevity can help clarify whether the association is universal or culturally specific.
A research team led by Akitomo Yasunaga of Aomori University of Health and Welfare set out to determine whether happiness really protects health, or whether the association disappears when factors such as age, income, education, and physical health are taken into account. Previous research has suggested that unhappy people may just be inherently unhealthy, falsely suggesting that unhappiness shortens lifespans if poor health is the real cause.
To find out, researchers followed 3,187 adults (aged 20 and older) living in Minamiizu, a rural Japanese town, from 2016 to 2023. At the beginning of the study, participants answered a simple question: “How happy do you think you are right now?”
Participants initially responded on a four-point scale, but because so few reported negative emotions, researchers combined the bottom two categories. This ultimately classified participants into one of three groups: happy (31.5%), somewhat happy (60.8%), and unhappy (7.7%). The team also collected information on education, marital status, economic status, BMI, and physical function. For the next seven years, deaths were tracked using official city records.
By the end of the study, 277 participants had died. Researchers found a clear pattern. Those who reported being unhappy at the start of the study were significantly more likely to die during follow-up. Even after adjusting for age, gender, socioeconomic status, and health measures, the unhappy group had an 85 percent higher risk of dying than the happy group.
The results were consistent even when the researchers excluded participants who died within a year, making pre-existing terminal illness less likely to explain the results.
Yasunaga and his team concluded, “The consistency of our findings with the international literature suggests that, despite potential cultural nuances in how happiness is experienced and expressed, the protective association between happiness and mortality may reflect a more universal phenomenon.”
Still, the authors caution that the study has limitations. Happiness was measured with a single question, which does not capture the full complexity of emotional well-being. Additionally, health status was assessed using self-report measures, which may be less accurate than clinical assessments. Importantly, the study did not control for lifestyle habits such as smoking, alcohol intake, diet, and physical activity, which can affect both a person’s well-being and risk of death.
This research was conducted by Akiyoshi Yasunaga, Ai Shibata, Yoshino Hosokawa, Mohammad Javad Khusari, Rina Miyawaki, Kuniko Araki, Kaori Ishii, and Koichiro Oka.
