Your little brother copies how you treat people, not just your shoes.

Imitation does not stop at the visible stuff. A younger sibling picks up the shoes and the slang because those are visible, and underneath that he is copying how you speak to waiters, whether you mock people who are struggling, what you do when somebody is left out. None of that gets taught deliberately. It is absorbed from the person he decided to become.

Choose one way you treat people and get it right in front of him this week: thank somebody by name, sit with the kid nobody sits with, say sorry out loud. He is going to copy something, and you get a small say in which.