The notion that children must be controlled, coerced, and hit is a vestigial cultural organ of society; it is unneeded and destructive. Neuropsychology has undermined this lie that children have to be controlled in order to be brought up well, as upstanding and virtuous people.
At roughly two years of age, children are growing and developing neurologically, and they have not created all the necessary networks to regulate their emotions.
This is why they become volatile and demonstrate aggression. It is not because kids need to be shaped into good people, but because they are still developing. Therefore, hitting them and controlling their emotions during this stage only causes trauma and harm. Ironically, it helps mold bitter, destructive, violent, traumatized, and depressed adults.