You can't easily discount culture and habit, nor can you easily account for it in studies. Cross-country comparisons are often surprising, but even then they bl

You can't easily discount culture and habit, nor can you easily account for it in studies. Cross-country comparisons are often surprising, but even then they blur within-country heterogeneity (is $country fatter on average/mode, or does it have a looooooong tail on account of a slightly higher rate of rare genetics?)