Offering a child a small treat (whatever it may be) might seem unobjectionable, because parent/carer and child both ‘win’. But what’s really happening here is that you’re implicitly teaching them that if they want something that seems appealing, to get it they will have to do things they don’t want to do. You’re essentially supporting a pattern of exchanging one’s happiness/dignity/ethical standards/morals for some prize.
Kohn has a gut feeling that behaviourist dog training techniques are bad, and he is quite right about that. But he has no explanation of why they are and how they are. All he has is (worthless) ‘evidence’ that they are.
If parents don’t “do something”, like impose a penalty or bribe to change their child’s behaviour, will the child continue hitting forever? No!