Second, tell them what you want them to do quite clearly, and praise them verbally for doing as they are told. First, encourage the new behavior. Provide praise and rewards before using discipline as a means of teaching. When it is time to discipline you must be consistent, which is difficult when parents are exhausted, particularly late in the day. If you are inconsistent, only responding to a child's misbehavior when you have reached your limit, the message coming across is one of anger towards the child, not towards the unacceptable behavior.
Parents often do and say things when they are angry and end up apologizing later.
Parents need to learn how to work together to develop a consistent approach to discipline. In a word - no. But there are many ways to encourage positive behavior and discourage negative behavior without spanking. Parents who feel sufficiently frustrated that they need to use physical, painful discipline should seek help finding more constructive ways to discipline. This help can come from their pediatrician, social worker, psychologist, or through parenting programs available through local schools and community organizations.