A sunny market day in Chong’an: chaos. Narrow streets crammed with diminutive but solidly built Miao grandmothers dressed in dark blue with frilled tea-towel turbans, grandchildren strapped to their backs in quilted pads. Some of the babies also wore “tiger” hats, complete with silver icons and tufted ears, to ward off bad luck. The grandmothers were no respecters of age …