I can make a study that shows 0 wars in the region for decades despite having an army, and say that the logical conclusion should be to disband the army.

People often quote research to mislead and push their narratives. Widen the scope and their narrative falls apart.

In this case it's about going past this (often western-ish) belief that all children are born good and that something in their lives makes them bad. I'd like to propose a different take: that some children will often test their boundaries upon others and choose to say some threats are no big deal, until they actually go through the pain. Amongst those who go through it, even if there's 1 who remembers the pain and refrains from committing the same act in the future, it's worth it. Caning won't stop everything, but it is but one part of the whole net to tackle problem youths, and has effects down the road.