How you play the board game with your little brother says a lot about how you’ll play everything else.

Playing somebody much weaker than you removes the competition and leaves only the question of what you are like. Nothing is at stake, so everything becomes a choice: whether you gloat, whether you bend a rule he will not catch, whether you let him think slowly without sighing at him. He is also learning what playing with you is like, and that lasts.

Play properly, explain the rules out loud, and beat him sometimes rather than always or never. Let him have the dice, the first turn and the thinking time. The same habits show up later whenever you are the one in the room who knows the most.