The research on rewards is a hundred years deep and it disagrees with itself, mostly because "reward chart" covers two completely different machines and people argue about them as if they were one.
The two machines
| A record of effort | A behavior contract | |
|---|---|---|
| What it measures | Things they did | Whether they complied |
| Direction | Only up | Up and down |
| A bad day | Pays less | Costs |
| Holds up over months | Usually | Rarely |
Most of the studies showing rewards backfire are about the second one, or about paying children for something they already loved doing. Most of the studies showing they work are about the first.
What a chart cannot do
Supply something that is missing. If getting out of the door is hard because the morning itself is chaotic, points will not build a routine, and a chart pointed at it becomes a weekly record of a child failing at something nobody equipped them for. The chart makes effort visible and worth repeating. It does not do the effort, and it cannot install what was never there.
That is not a small job. A child who is told off six times a day and noticed once is not short of feedback, they are short of the other kind. A record that only ever grows is one of the few things in a hard house that is not also a scoreboard of failures.