The children start showing the telltale signs of the decay and dissatisfaction of modern life as early as the age of seven nowadays, as their diets, screen time and lack of exercise see their bodies start to hit the buffers before they're old enough to ride the scariest of fairground rides.
This comes from the Gateshead Millennium Cohort study, which tracked a group of children over the course of eight years, monitoring their activity levels and discovering that the first slump in being bothered about anything hits the poor modern youngsters between the ages of seven and nine.
Their numbers showed that the average seven-year-old boy managed an hour and a quarter of quantifiable exercise per day, which fell to one hour and ten minutes by nine, then just one hour by the age of 12, when exercise means running really fast to plug a thing into its charger before it shuts itself down and leaves them with nothing to do during a painfully boring restart process.
Girls are even less bothered, managing just 47 minutes of exercise per day by the age of 12. Making them walk to school even if it's raining would seem to be the best solution, even if it means we lose a few more to local predatory paedophiles. [Gateshead Millennium Study via Telegraph]