My son, the enigma
About a year ago, we started giving the kids chores. They were constantly complaining that they didn't have any money, and we were constantly unhappy with the state of our house, so we gave 'em lists of housework to do. My daughter took to it okay. She balked at some jobs which she felt were pretty gruesome and deserved more pay. But overall, she liked earning money and did most jobs. For my son, if it was family cleanup day he'd pitch in. But if mom & dad were busy and he was left with a choice to play a video game or earn money cleaning the house, he'd play a video game. Money didn't motivate him at all.
For the most part, we let that stand. If he didn't want to earn money, he could miss out and that was fine. However, there were some things on the list that were not optional, such as keeping their rooms clean. When the rooms didn't get clean, I attached what I thought was a pretty serious consequence -- any toy not in its proper place gets thrown out. Again, for my daughter, this was fairly effective. Her room got mostly clean, and usually stayed that way. But for my son, this was a wonderful negotiation. "If I don't clean up, you throw these things away?"
I nodded somberly, "Yep."
"Okay," he replied. And then he left his room a complete mess and went outside to play with the neighborhood kids instead. Of course, I called his bluff. I put a ton of his toys in a garbage bag. Only it turns out he wasn't bluffing. He saw the bag and shrugged it off. It was almost as if this was a cost vs. benefit calculation for him -- the cost of a free afternoon was giving up some toys? Yeah, worth it. Done. As a bonus, he got me to clean his room for him.
I did not see that one coming.