This Lego structure represents unilateral evolution. The first light blue portion is a maze of dead ends with one path leading to the next stage of human culture. This earliest culture represents so-called simple hunter gatherer societies. In the next section there is one large door with a smaller door leading out. This represents feudalism or societies with city states, that have a well-defined religious and upper class. Only a few societies manage to pass through the small door. Where they advance into semi-modern thinking societies, as the car crash represents many societies get stuck at this point and then revert to an earlier stage. The white plank represents cultures that have successfully made it to industrialization. However if a civilization becomes industrialized it may still not reached the peak of civilization. This peak of civilization is represented by steering wheel, a fully industrialized society. Usually whichever society the theorist belongs to.