I've just come across a (very basic) description of Kohlberg's stages of moral development, and I found the section on the Pre-conventional level of moral reasoning rather suprising.
In particular, stage one, obedience and punishment orientation:
The pre-conventional level of moral reasoning is especially common in children, although adults can also exhibit this level of reasoning. Reasoners at this level judge the morality of an action by its direct consequences. The pre-conventional level consists of the first and second stages of moral development, and is solely concerned with the self in an egocentric manner. A child with preconventional morality has not yet adopted or internalized society's conventions regarding what is right or wrong, but instead focuses largely on external consequences that certain actions may bring.
In Stage one (obedience and punishment driven), individuals focus on the direct consequences of their actions on themselves. For example, an action is perceived as morally wrong because the perpetrator is punished. "The last time I did that I got spanked so I will not do it again." The worse the punishment for the act is, the more "bad" the act is perceived to be. This can give rise to an inference that even innocent victims are guilty in proportion to their suffering. It is "egocentric", lacking recognition that others' points of view are different from one's own.There is "deference to superior power or prestige"
What surprised me is the example of moral perception in relation to degree of punishment.
While there does seem to be support for the idea (please feel free to chime in on that question with more authoritative answers!) that spanking can be an effective means of eliminating undesireable behavior, there is a significant amount of evidence citing the general levels of negative impact corporal punishment can have.
Anecdotally, lower levels of punishment seem to have no correlation with Kohlberg's Stage One model. My son does not seem to equate punishment as indication that an action is 'morally wrong'. He does understand that if he repeats the behavior, he will likely have to repeat the punishment, but given the experimentations with defiance and self-assertion common to three year olds, he does tend to repeat the behavior at least a few times, in an attempt to push boundaries and see what he can get away with.
Additionally, the one time my son has been exposed to corporal punishment (another child's grandmother decided to spank her son in daycare, right in front of my son, much to my anger and frustration), my son showed no indication that he felt that the boy had done anything wrong, but rather was obsessively concerned as to whether he was okay, and why she would do that to him.
This seems counter to the idea that the punishment instills the idea that the actions which precipitate the punishments are "morally wrong", as Kohlberg seems to be asserting.
Am I misunderstanding Kohlberg's Stage One? Is his theory generally considered reputable? Most importantly, is there observational data upon which his theory is based, which supports the conclusions he draws?