IN THE UK in 1965, the most common age of death was in the first year of life. Today the most common age to die is 87 years old. This startling statistic comes from a remarkable new book, The Longevity Imperative, by Andrew Scott of the London Business School. He notes, too, that a newborn girl in Japan has a 96 per cent chance of making it to 60, while Japanese women have a life expectancy of nearly 88. Japan is exceptional. But we are living longer everywhere: global life expectancy is now 76 for women and 71 for men (clearly, the weaker sex).

This new world has been created by the collapse in death rates of the young. Back in 1841, 35 per cent of male children were dead before they reached 20 in the UK and 77 per cent did not survive to 70. By 2020, these figures had fallen to 0.7 and 21 per cent, respectively. We have largely defeated the causes of early death, by means of cleaner food and water, vaccination and antibiotics. I remember when polio was a great threat. It is almost entirely gone, as is the once vastly greater peril of smallpox.

This is humanity’s greatest achievement. Yet our main reaction is to fret over the costs of an “ageing” society. Would young and middle-aged adults prefer to know that they and, worse, their children might die at any moment? We know the answer to this question.