From The Economist, two researchers trying to understand how crowds behave:
Imagine that you are French. You are walking along a busy pavement in Paris and another pedestrian is approaching from the opposite direction. A collision will occur unless you each move out of the other’s way. Which way do you step?
The answer is almost certainly to the right. Replay the same scene in many parts of Asia, however, and you would probably move to the left. It is not obvious why. There is no instruction to head in a specific direction (South Korea, where there is a campaign to get people to walk on the right, is an exception). There is no simple correlation with the side of the road on which people drive: Londoners funnel to the right on pavements, for example.
This reminds me of a story that my friend Chris likes to tell (apologies if I mess up any details). One day when his sister was in college, she was riding her bike down the sidewalk and had to turn a corner. There was another biker coming the opposite way. They both swerved. She "naturally" went to the right and he went to the left--but it was his left, her right. Crash. The other biker was from South Africa, where they drive on the left.
Until I read the above, I had assumed that people walked the way that they drive, but it appears that I was wrong. It will be interesting to see how South Korea's efforts to overturn the emergent order work out. At the moment I can't actually recall the dominant walking pattern in Jamaica, where they drive on the left, but in any case it is probably confounded by the high numbers of American tourists. Personally I just wish people would be a little more careful taking sharp lefts around corners.