I do not want to lump all children into two categories, but I will say that it seems to me that some children are sensitive to what their parents think and feel, and some children, though they definitely crave the love and affection of their parents, are born into this world not so worried about how their parents feel about their behavior: they have a heart to conquer, to win, to lead. Many children have a combination of both of these spirits, and all children were created by God with the personalities that He gave them. The more sensitive children respond quickly to punitive discipline. Having their parents spank them, or put them in time out, breaks their hearts, but they cover it up to please their parents and keep them happy. They act as good as possible to avoid punishment. If they choose to disobey, they often are sneaky; not outwardly rebellious. The children with "strong wills" are more likely to question their parents. Punitive discipline sets them up for a life-long fight. Letting a spanking in any way affect them proves to the world that their parents won, and they will not have it.
Gentle discipline addresses both personalities, because the parent embraces the role of a teacher, a discipler, who comes alongside the child, works with the child's personality, and guides the child in the right direction. Christians who use gentle discipline recognize that a child's heart is what matters, and that outward good behavior does not always mean that the heart is in the same place. These Christian parents seek to teach their children right from wrong, yet they also do not mislead their children into thinking that outward good behavior is all that counts. They allow God to work in their child's hearts. They refuse to shame their children into acting good. They treat their children with the same grace God bestows on them.