Do you want to feel old? The younger brother of rock, Liam, needs a hip replacement. At 49, the ex-Oasis leader is suffering from arthritis, which he seems to be approaching with customary stubbornness. He is not having the surgery his doctor recommended because hip replacements are for old people. Who wants that?

He said he would rather be in pain than have his hips replaced.

Middle age isn't always rock and roll. When you can pull a muscle just by getting up too quickly from the sofa, and when the only phone number you have left is that of an osteopath, there is a point. Women are supposed to mourn the fading of their looks in their 40s, but nobody is traumatised by the odd grey hair or wrinkling. Our bodies may stop doing what we need them to do one day, and that is what we secretly fear.

Generation X can't afford to get old. The body of Gallagher has to hold out long enough to headline this summer. The rest of us still have teenage kids to launch into the world, our own parents to look after, pensions that will keep us working into our 70s, and bosses that are just waiting for a chance to put us out to grass. We don't have time to lose.

The stigma still clings to both disability and age, and even the Queen is afraid of using a wheelchair in public if she is seen as old. The words give the game away. Is it really aging itself we fear, or the negative ideas attached to older bodies which we subconsciously internalize, like the idea that teenage girls are too fat or skinny, or just?

A new book by a professor of epidemiology at Yale argues that assumptions about growing older have a direct impact on how we cope. Levy's research found that people with optimistic ideas about aging lived seven and a half years longer than pessimists. She found that older people's memory, balance and walking speed improved when they were exposed to positive stereotypes.

It's similar to research that suggests girls score worse in math tests if they're told in advance that boys are better at it. Levy's work shows that people with positive beliefs are less likely to develop dementia.

It is possible that cheerfulness has a chemical impact on stress hormones. It could be that people who are confident of thriving in old age are motivated to keep fit, eat healthy and push for medical interventions if something goes wrong, while those who are less confident are resigned to falling apart.

There is a risk of falling into a sort of medical doctrine that blames sickness on an individual's failure to be sufficiently upbeat rather than the structural inequalities driving public health. If Levy is correct, we should be concerned that ageism is still the most socially acceptable form of hate speech. We should be worried about how it is fueled by economic resentment of baby boomers and how it is not worth closing pubs to save old people. When did knee jerk prejudice start to bow to facts? The typical person dying of Covid lost a good decade of life they would otherwise have enjoyed.

During the Pandemic, age subconsciousism may have cost lives, making us too slow to protect care homes. According to Levy, it has been killing the middle aged for years, making them feel bad not just about their neck. We are so conditioned to see the older body as a source of shame that we don't complain about it to the doctors. Maybe we should expect better. If Levy is correct, lives are dependent on it.

  • Gaby is a columnist for the Guardian.