When Ralph and Piggy are swimming in the water hole, Piggy decides to make a sundial so they can tell the time more accurately. Piggy is attempting to make a society like the one they left behind.
On pages 63-64, a ship passes by and because Jack wasn't watching out by the fire, it passed by without anybody to signal to it. As a result, they are all arguing. Piggy decides to go on Ralph's side by confronting Jack for his irresponsibility, but Jack smacks Piggy and breaks his glasses.
Piggy's actions show he is reacting in an orderly way, supporting the values of the group which would aid in their survival.