Fascinating article - much 'food' for thought. Though the life expectancy increase is not as dramatic as it is sometimes taken to be. As you rightly point out, a major factor was the reduction in child mortality (the biggest step change being the development of vaccines). Prior to this, if people survived childhood they often lived well into old age, and there were probably no more people dying at age 32 than they do these days. It was the huge number of infant deaths that dragged the average down.