I think it's a cool study. You humans KNOW that we dogs have your back and we care about you. LOTS. And it makes sense that we wouldn't like someone who is not nice to you. But honestly, I'm just a TINY bit concerned about what would happen if the PONs in this household were in this study. Well, maybe not Einstein - but as for me....treat refusal is something I can't even IMAGINE. The FG is not as crazy a chow hound, so I can see him refusing. And Einstein, well he would no doubt bark and voice his disapproval. But me....OK. OK. I would refuse the treat. It's the right thing to do. Besides, my human would then treat me for being a good dog. So I still get the treat. Phew. Ethical dilemma solved.
Have a good one! And don't refuse to open someone's jar.