the only way the boulder will move is if the golden child moves it. Otherwise any attempts by the villagers will be a waste of their time although they will try to move the boulder. you need to complete the idol, the lagoon, and level 3 fertility in order to create the birth of a golden child. You will have to drag a nursing female to the lagoon and drop her in it. In any case, if you create the golden child as early in the game as you can, he sure does a lot of neat things.