Those who feel younger are more likely to do activities that keep them young. Photo: Marcus Aurelius / Pexels
A psychology professor at the University of Luxembourg says most of us feel an age that bears no relation to how old we really are.
'People who think more positively about ageing are more open to new things' - Listen to the full interview here
Anna Kornadt is head of the university's Institute of Lifespan Development, Family and Culture and told Sunday Morning most people over 40 think they are 20 percent younger than they really are.
She said there was a clear link between feelings about ageing and behaviours that contribute to ageing.
"If I think that everything gets worse when I age, then I will probably not do anything to counteract that - it demotivates people to take action, so this might end with you ageing worse than someone who thinks more positively about ageing."
"If I feel younger, then I might do more physical activity, I might take more care with the food I eat, and I might surround myself with people who do enjoyable activities."
However, it was not just a case of telling everyone to exercise more as they aged, she said.
"If I exercise and feel horrible afterwards - my knees hurt, everything hurts, I'm just exhausted - it might not make you feel younger.
"It has to be behaviours and actions that you can still do and feel good for yourself. So maybe not running marathons, but instead going on walks or eating better."
Professor Anna Kornadt, of the University of Luxembourg. Photo: Sophie Margue
Context made a "huge difference", she said. If you were in a retirement village, for example, it was possible to feel younger than you really were.
"I might think I'm in this nursing home now, but everyone else is doing worse than I am, so I feel pretty young. It depends on your situation - why you ended up there, whether you feel that you belong there, it can go both ways."
So could you just fake your age?
"It would probably not work! This age you feel - it stands for something: what you sense in your body, the activities that you do, the feedback that you get from your social surroundings, how you think you are doing in comparison to others."
Thinking negatively about ageing was related to stress, and worked both ways, she said. "It might be an indicator of stress, but it also might cause stress which has physiological consequences.
"It's also about mindset: what goals do I still set and how do I think I can control what's happening to me? These are all mechanisms that turn this subjective ageing into outcomes."
Was it helpful to delude ourselves into thinking we were better or worse looking than we really are?
"It's not a delusion - it's a way of taking in your surroundings and interpreting what is happening to you and putting it into action. That's what psychology is about.
"If you're in a very powerful position, you might feel bodily larger than you are. The assumptions we make about ourselves play a big role (in our behaviour).
"People who think more positively about ageing are more open to new things, open to embrace change, they have more resources to deal with changes, and they interpret them differently and not as negatively.
"It's not about stopping time, not saying I'm 50 and want to be 25 again. It's saying, 'I'm 50 and I'm fine with being 50 because I feel 25. This is more the mechanism that we're talking about.
On the other hand, it was also normal for people younger than 25 to feel older.
"Then around 25 there is a switch: the subjective age bias turns to the negative and people start feeling younger than they really are."
Most of these studies were from a Western or European context, but a recent study in Burkina Faso found people just felt the age they were.
"Age means something different in these countries ... these are places where life expectancy may not be as high and so people want to grow older."
Ultimately, ageing was about your mindset, and not being concerned about others' reactions, Kornadt said.
"We all have these ideas of what older people should be and what they should and should not do. If I'm in a social context where I'm not 'allowed' to do these things, this might keep me from doing it."
"Why do we as a society have these ideas about ageing? This should be taken into account when considering what ageing well means for people and for our society."