“The most superficial observation is sufficient to show that in the main the legal sense is far less developed in little girls than in boys. We did not succeed in finding a single collective game played by girls in which there were as many rules and, above all, as fine and consistent an organization and codification of these rules as in the game of marbles. A significant example in this connection is the game of ‘Marelle’ (Engl., Hop-scotch) (also called ‘la Semaine’ or ‘le Ciel’) which consists in hopping on one leg and kicking a stone through various sections drawn on the ground representing the days of the week or anything else one likes. The few rules embodied in this game (not to put the other foot down, to make the pebble go into the right square with one kick, not to let the pebble stop on a boundary line, permission to rest in a special section called Heaven, etc.) show well enough how possible it would have been to complicate the game by constructing new rules on these initial data. Instead of which girls, though they are very fond of this game and play it much oftener than boys, have applied all their ingenuity in inventing new figures. For the game of Marelle exists in a multitude of forms; the sections drawn in chalk on the pavement succeed one another in a straight line, in parallel lines, in the shape of a spiral, a circle, an oval, of the pipe of a stove, etc. But each game in itself is very simple and never presents the splendid codification and complicated jurisprudence of the game of marbles. As to the game of marbles itself, the few little girls who take any interest in it seem more concerned with achieving dexterity at the game than with the legal structure of this social institution.” – Jean Piaget, The Moral Judgment of the Child (trans. Marjorie Gabain)