This is one of the better-evidenced findings in the psychology of ageing. The Yale researcher Becca Levy has spent decades showing that the beliefs we hold about our own ageing measurably shape what happens to us. In her long-term studies, people with more positive beliefs about growing older lived, on average, around seven and a half years longer than those with negative ones — and did better on memory, recovery and wellbeing along the way.
The story, in other words, isn't just descriptive. To a real degree, it's causal.