Asked by: Jason Philips, USA
We’re not all like Bao Xishun, but the average height, at least in Western society, is increasing because of better childhood nutrition and sexual selection. But the tendency of women to find men taller than six feet (183cm) more attractive can’t be extrapolated upward, and people above 6ft 2in (188cm) are much more likely to suffer back problems. Above 6ft 8in (203cm), and the heart strains to pump blood round the body.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.