From Ami Magazine’s interview with “Master Mechanech”, Reb Dovid Levy (April 17, 2019):
Ami’s Rabbi Frankfurter: Many gedolim I’ve spoken with are of the opinion that changes must be made with regard to chinuch for the present generation. Do you agree?
RDL: We certainly need a different approach. As the generations have changed, so too has the way to relate things and communicate. For example, in previous generations, a parent or teacher would slap a child if he did something wrong and it would have a positive effect. Nowadays, slapping a child is counterproductive.
Ami’s Rabbi Frankfurter: One might argue that we are prohibited from deviating from the traditional ways.
RDL: The reason we can’t do that today is not that the message is different, chas v’shalom. The reason is that the slap might distance the child from Torah.
The prohibition against chadash is against having a different goal, not against having different tools. Our Torah remains the same. Truth remains truth, and we must never deviate even a hairsbreadth. But the way to convey the truth does change. Nowadays we need a lot of positive reinforcement to educate and train our children to do what is right, which is actually not a modern idea.
The Gemara in Bava Metzia (85a) says that when Rabbi Elazar ben Rabbi Shimon passed away he left a son who was doing terrible things. But the Tanna’im called him Rebbe even though he wasn’t worthy of that honorific, because they used it as a tool to bring him back until he actually became a Tanna. So I’m not borrowing ideas from contemporary psychology, I’m talking about things that Chazal did.