They begin to empathize.
Not all second graders, but some, show signs of empathy. If he sees a classmate hurt himself on the playground, he may wince in pain. If he sees someone being picked on, he’ll feel sorry him. And if he sees someone laughing or showing great pleasure, he’ll feel happy.
What you should do: Smile. Your little one is growing up. Kids who empathize generally make strong friendships and are well-liked by peers.