There is no such thing as 'Chinese culture' or 'American culture'. China and the US are political entities comprising as many different perspectives on life as they do ethnic groups, family units or even people. Yet, if one wants to talk about cultures at all, one invariably falls to generalising.

This is not some sort of false intellectual exercise. The reason that generalisation is so common is that it taps into human instinct. There are at least two compelling psychological incentives behind the impulse. First, there is what some psychologists call 'cognitive parsimony'. The brain has limits to how much it can store, so people spontaneously edit, organise and simplify. This can be seen in the way that young children like to talk over the chief events of the day - a way of eliciting the help of adults to sift through experience. Adults are more practised but they, too, yearn to talk over novel events to help sort experience into order.