Were you as suspicious as I was this week to read new research into the way our brains develop and age? It all seemed so pat, so neatly boxed-off and predictable. The study, conducted at Cambridge University and involving brain scans of nearly 4,000 people aged between nought and 90, claims to have identified five key stages of ageing. They found our lives are divided by four key ‘turning points’ between each phase, which are: childhood, adolescence, adulthood, early ageing and late ageing.

Well, so far, so fair enough. It was the rigid definition by age of each stage that bothered me. Apparently when we’re nine, we move from childhood to adolescence. That second phase lasts until we’re 32 (really? Adolescent until 32?) when we become adults, mentally and emotionally speaking. Nothing much changes until 66, when things start to deteriorate. That’s a relatively slow process until we’re 83, when we really go over the cognitive cliff.

Hmm. I just don’t buy it. It doesn’t correspond with what I’ve observed in my 77 years on the planet. People age, both mentally and physically, at vastly different rates. 

Some people never really grow up, remaining childish and immature their whole lives. Others hit middle age in their teens (Richard was in the same class as Philip Hammond, a future Conservative chancellor, and says he was about 40 when he was 16). Some people in their 90s sound more like they’re in their 50s.

The Cambridge researchers based their findings on physical changes to the brain revealed by the scans. But how can they be so sure? Back in 2007, The Lancet published the extraordinary case of a 44-year-old French man, who had led a perfectly normal life despite having… well, no brain! 

Routine hospital checks revealed to astonished doctors that there was mostly liquid where his brain should have been, with just a thin layer of cerebral tissue left. 

He had a family, a job, and an IQ of 84 (very slightly below the normal range). Brain experts are still at a loss as to how he has led such a successful, if unremarkable, life.

Sorry, Cambridge. I’m not sold.