Blurb:

A popular poster from Myanmar lists food pairings that should be avoided, sometimes at all costs. Coconut and honey taken together, for example, are believed to cause nausea, while pork and curdled milk will induce diarrhoea. Worst of all, according to the poster, many seemingly innocuous combinations that include jelly and coffee, beef and star fruit, or pigeon and pumpkin, are likely to kill the unwary consumer. But why are these combinations considered dangerous, even fatal? Our provisional answer, derived from the statistics of known cultural behaviour and supported by simple computer simulations, is that such food norms, along with many other social belief norms, are influenced, not just by actual risks, but also by strong forces of cultural learning that can drive and lock in arbitrary rules, even in the face of contrary evidence.