Life stories from the convent
In the 1930s, the mothers superior of a Catholic order in the USA asked their young novices for something simple: a short, handwritten account of their lives. The women were in their early twenties and about to take their vows. They wrote about their childhood, their family and why they wanted to enter the convent. Some texts sounded matter-of-fact and brief. Others were full of anticipation, gratitude and confidence.
Decades later, researchers came across these pages. They analysed the life stories of 180 sisters, counted how many positive emotions appeared in them and compared this with how the women's lives went on. The result was astonishing: the sisters whose texts sounded the most cheerful reached a very old age considerably more often than those whose texts were the most matter-of-fact.
This is all the more remarkable because all the women lived under very similar conditions for decades: the same daily routine, the same meals, the same work. Many of the differences that usually distort such comparisons did not apply here.
The study raises an intriguing question: can the way you look at your life influence how quickly you age? Your chronological age counts the years since you were born. Your biological age describes the actual condition of your body, for example how much strain stress hormones and silent inflammation have already put on it. This seems to be exactly where your inner attitude comes into play. But how exactly?
What good feelings change in your body
Part of the answer lies in stress hormones. A research group in London followed just over 200 office workers throughout an entire working day and repeatedly asked them how happy they felt at that moment. At the same time, the researchers measured their pulse and the cortisol in their saliva. Those who felt happy more often had less cortisol in their bodies over the course of the day, and the men also had a calmer pulse.
Picture a good shock absorber. The potholes in the road stay the same, but you feel them less harshly. Positive emotions work in a similar way: they do not take away the strains of everyday life, but they cushion how strongly your body reacts to them. In the long run, this can dampen silent inflammation, which is considered one of the drivers of biological ageing. Read more here (Article: Stress and relaxation).
It is not quite that simple, though. One of the largest studies on the subject, the British Million Women Study with around 700,000 women, came to a surprising conclusion: those who felt unhappy did not automatically live shorter lives. Often it was the other way round, and those who were ill became unhappy as a result. Once the researchers had taken health status into account, the link largely disappeared.
So happiness at the push of a button is no recipe for health. The evidence is much clearer for a related trait: optimism.
What happens when you follow optimists for decades?
Optimism does not mean seeing everything through rose-tinted glasses. It means expecting that things will, on the whole, turn out well, and trusting that you can contribute to that yourself.
A team from Boston examined how much difference this attitude can make. It analysed data from almost 70,000 nurses who were followed for ten years, and from around 1,400 men whose health was tracked over 30 years. The most optimistic participants lived on average 11 to 15 percent longer than the least optimistic. And they were considerably more likely to reach the age of 85. The difference remained even after the researchers had taken pre-existing conditions, exercise, diet and alcohol into account.
An analysis of many studies with around 230,000 people in total points in the same direction. Optimists had around a third fewer heart attacks or strokes. Experts suspect that they process strain more quickly, are more likely to tackle problems actively and take better care of their health.
Optimism does not mean overlooking problems. It means facing them with the expectation that you can solve them.
That leaves the question of whether you either have this attitude or you don't.
Gratitude: How to train a hopeful outlook
The good news: optimism is only partly innate. Twin studies suggest that about a quarter to a third of it lies in our genes. The rest comes from experiences and habits, and habits can be changed.
One of the simplest ways is through gratitude. Psychologists Robert Emmons and Michael McCullough asked students to write down five things they were grateful for once a week for ten weeks. A comparison group noted down the week's annoyances instead. At the end, the grateful group looked ahead to the coming week and at their lives as a whole with more optimism. They exercised more and reported fewer physical complaints.
Behind this lies a simple mechanism. Our brain naturally pays more attention to dangers and problems than to what is going well. For our ancestors, this was vital for survival. If you regularly and consciously name the good things, you deliberately steer your attention in the other direction. Over time, this becomes a way of seeing that still finds bright spots even in difficult phases.
How can you build this into your everyday life?
Small exercises that change your perspective
One of the best-known exercises is called "three good things". In the evening, write down three things that went well today and briefly why. They can be small things: a good conversation, the sun on your way to work, a successful dinner. In a study by psychologist Martin Seligman, participants were asked to do this for a week. Many carried on voluntarily, and even six months later they felt happier than at the start.
I was sceptical about this exercise myself for a long time. Still, I tried it out over a longer period and noticed how much it helped me keep looking ahead, even in difficult phases. At some point I even started looking forward to reflecting on the good things of the day in the evening instead of getting stuck on the negative.
Optimism can be practised in everyday life too. When something goes wrong, it helps to ask what part of it you can influence and what the next small step would be. A good rule of thumb: when you catch yourself brooding or doubting, imagine a good friend telling you about exactly your situation and how much they are doubting right now. How would you react? You would probably reassure them, point out the good things about their situation and put the difficult parts into perspective. That is exactly how you are allowed to treat yourself, too, looking at yourself for once from the perspective of a good friend.
As with training, it is not the single evening that counts, but the repetition. A few minutes a day are enough once they become a habit.
For your biological age, what counts is not whether you are always in a good mood, but whether you keep finding your way back to seeing the good.
Where the BioAge test helps and where it doesn't
The BioAge test also asks how happy you feel overall and lets you assess how grateful and hopeful you are about your life. It can be a nudge to take an honest look at how you are doing right now. But it is no more than a first check-in. It can in no way replace an open and honest conversation with someone you trust or with a professional.
Frequently asked questions about happiness, optimism and biological age
Isn't optimism naive?
Not if it stays realistic. Healthy optimism takes problems seriously and trusts that they can be solved. It would be naive to ignore difficulties or to force yourself to always be in a good mood.
Will I become happier as I get older?
Many studies suggest so. Life satisfaction often follows a shallow U-curve: it hits a low point around midlife and then rises again for many people.
Does exercise help against a bad mood?
Yes. Regular exercise has been shown to lift your mood, and even brisk walking can help. Read more here (Article: Endurance).
How can I tell whether a low is more than just a bad patch?
Lows are part of life. But if low mood, lack of drive or loss of joy persist almost every day for more than two weeks, you should have it checked by a doctor. Depression is an illness that can be treated well.