I am the father of three boys. We have a family tradition to measure every child’s height on their birthday. The fast-growing teenagers always look forward to the confirmation that they have grown a lot, especially if it means passing the height of one of their parents! There is much banter about who is taller, and who will be taller than who when they finish growing. (It is also humbling for the parents; I lost my tallest status a few years back and am likely to be passed twice more in the...