When most of us think of reinforcers, we think of things like candy, high fives, and bubbles. Obviously those things are only reinforcing to people if they enjoy those things. 
It’s interesting to observe children because we see at a very young age what is and isn’t reinforcing. When the baby spits food back into your face, I think it’s clear that either it’s really reinforcing to see your reaction, it feels good, or it tastes or feels really awful.
On my very first session with families I ask what is reinforcing to their child. Sometimes families are quick to respond with: his truck, cookies, or playing outside. Those things can definitely be reinforcing to your child but there are so many other things that can also be reinforcing that you may not have thought of.
