During the 10 years I've been working as a Behaviour Consultant, I've heard the words "pick your battles" from educators thousands of times. What they mean is that if you see your chlid acting out, you have a choice to make: (a) you intervene and be consistent with the consequences you set, or (b) you simply do not intervene. No educator will tell you to set a boundary that you later cannot follow through on. Doing that could make your words lose the power they have, and could teach the child that she can get away with breaking the rules.
My experience has shown me that consistency is a key component in parenting. I am not only talking about the consistency between words and actions (e.g., if I say that I will give you a cookie, that I will deliver the cookie), but I am also talking about consistency in terms of responding to inappropriate behaviours.
Many times, in our work, we use a strategy called extinction (that is, extinction of the reinforcer that keeps the inappropriate behaviour going). In other words, extinction means that if a child misbehaves (e.g., screams) to obtain candy, we will not give him candy any more when he misbehaves. We know that if we are consistent with not giving the screaming child the candy, and if at the same time we consistently provide the candy when the child asks for it nicely, we will reduce screaming and increase appropriate requests for candy.
Many times, parents start implementing extinction plans and they find that the child's behaviour escalates (i.e., increases in frequency, duration, and/or intensity). With extinction, that increase is expected and it does not mean that the strategy is not working. After all, the child knows that screaming gets him candy, so he will try and try even harder, louder, or for longer periods of time. This is a crucial moment in the implementation of a behaviour plan that uses extinction. If a parent gives in and ends up giving the candy when the child screams louder or for a longer period of time, that parent might be teaching the child "if you want to get candy, screaming isn't enough, you need to scream louder or longer to get it."
Therefore, being consistent is extremely important when changing behaviour. We need to make our words match our actions, giving our words power and giving the child a reliable and consistent parent.
Gabriel Canal, Behaviour Consultant- Positive Parenting and Behaviour Support Program- FVCDC