Visual cues that imprints a positive identity
Kids are visual and need repetition to build a habit, and a chart on the wall gives them that just by being seen every day.
Here's the psychological principles I used when designing them.
Your Environment Shapes Your Habits and Behavior
In Atomic Habits, James Clear calls environment "the invisible hand that shapes behavior" — and the first of habit change is simply "make it obvious," because a visible cue is what actually triggers a habit, not motivation. A chart on the wall works as that obvious cue: seeing it prompts the behavior automatically — which then builds a habit.
Identity First, Reward as Support
Encourage your child with identity, not reward: "You're becoming a boy who uses the potty," or "You're a child who uses your hands the right way" — said while pointing to the chart.
A sticker supports the process, but it isn't the purpose. The child behaves well because of who they believe they are, through the visual clue on the chart.