My 3yo's classmate was having a hard time and had to play on his own for a bit. Upon rejoining the group, he started drawing on her paper instead of his own. The teacher told him to stop & asked my kid if she had any feelings about it. Her: *thinks* "Okay. But don't do it again."
Yeah it's almost like kids are naturally that way if they're not constantly exposed to sociopathic behavior being rewarded and demonstrated by the adults around them...