The facts that Eastern and Western scores converged in ancient times and that the East then led the world in social development for twelve hundred years do not disprove long-term lock-in theories, any more than the fact that the West has led for nearly the whole time since the end of the Ice Age disproves short-term accident theories; but again, they mean that a successful theory will need to be rather more sophisticated and to take account of a wider range of evidence than those offered so far.
