Rebuke the action, not the actor

Don't say "you are a bad boy". Instead, say "Good boys like you do not behave like that."

Our actions are consistent with our self-image i.e. we behave according to how we see ourselves.

If you think you are an honest person, you may still lie but it would make you uncomfortable and you would want to avoid it as lying is inconsistent with how you see yourself.

In the early years, parents and teachers can help shape the positive self-image of a child by carefully choosing what they say to the child.

When trying to discipline a child, don't make a personal attack. Differentiate between the bad behavior and the person.

So when someone does something horrible: 

• Don't say:
  • You are a naughty boy.
  • Don't be a bad girl.
  • You are a horrible person.
  • You always do this
• Say
  • You are a good boy and that's bad behavior.
  • You are a good girl. Don't behave that way.
  • Why would a nice person like you do such a horrible thing?
  • I didn't expect this from someone like you.
  • Good people like you don't do things like that.
  • We don't do things like this in our family.

Using the right words builds their positive self-image while instilling moral values in them.

References:

Fierce intimacy by Terence Real