A decades-old study on nuns found something surprising about optimism and lifespan

One of the most fascinating pieces of evidence linking optimism to a longer life comes from the ‘Nun Study.’ Beginning in the 1930s, researchers collected autobiographical essays written by young nuns, and decades later compared those writings with the participants’ health records. Women who naturally expressed more positive emotions in early adulthood lived, on average, significantly longer than those whose writings reflected fewer positive emotions.

While optimism alone does not guarantee a long life, the findings suggest that emotional wellbeing deserves as much attention as physical health. The US National Institute on Aging also highlights that chronic stress can negatively affect physical and mental health over time, while managing stress contributes to healthier ageing.

Actor Dick Van Dyke, who turned 100 at the end of 2025, offers a modern example of the same idea. Promoting his book ‘100 Rules for Living to 100: An Optimist’s Guide to a Happy Life,’ he explained his outlook simply: ‘I never wake up in a bad mood.’

People who think positively often manage stress better, recover emotionally faster after disappointments, and are more likely to stick with healthy habits such as exercising regularly, sleeping well and attending medical check-ups — small, everyday behaviours that researchers say play a large role in how people age.

Image: Wikimedia Commons/by Gage Skidmore