Same flavours, different taste buds: a theory for predicting social norms for specific behaviours across cultures.

Behavioural norms vary across cultures, and they vary in distinct ways for different behaviours. We show that this variation is not random but highly predictable. We introduce the Moral Flavours Model, a theory proposing that norms emerge from three factors: how much moral concern a behaviour evokes overall, its 'moral flavour' (the type of concern it evokes), and societies' 'moral tastes' (their sensitivity to different types of concern). We demonstrate that this simple framework predicts 76% of the variance in moral norms across 19 morally contentious behaviours in 42 societies, and 88% of the variance in everyday norms across 150 situated behaviours in 90 societies. Remarkably, the same societal tastes predict both profound moral issues (like euthanasia) and mundane behaviours (e.g. whether it is okay to sing on a bus). These fundamental tastes therefore have the potential to predict a society's entire normative landscape. By establishing a high-performance, quantitative theory of cultural variation, this work provides both a powerful predictive tool and new insights into how culture shapes human judgement.