As a therapist specializing in helping families and adolescents get from the age of 13 to 18 as smoothly as possible, I spend a lot of time pondering the consequences enforced for undesirable behavior. Two facts are paramount when it comes to consequences-they must be enforced consistently and they must be reasonable. It is also preferable if they are known in advance, but if parents are consistent, that aspect will be taken care of naturally.
The biggest key to having consequences shape behavior is to have them enforced consistently. A child who knows he will be grounded if he misses curfew because that is what happened the last two times is much more likely to get home on time than the child who was grounded when he missed curfew but not the other time. For the second child there is a bit of a 'lottery' aspect to punishment, and as the lottery people are fond of telling us 'it might be you'. While it is almost impossible to be 100% consistent, and I certainly do not advocate a 'iron clad' rule aspect, where no extenuating circumstances are taken into account, all parents should keep in mind that the more inconsistently rules are enforced and the less consequences are given, the less likely children will be to follow the rules.
Another major issue that comes up time and again in my practice is the need for reasonable consequences. Many parents will start with a rule such as 'if you cut school, you will be grounded for a day'. When they find that a grounding for a day had no effect, they increase the time to a week, then a month, and occasionally six months or a whole school year. A consequence that has gone to this extreme is no longer useful-if it ever was in the first place. A child who is grounded for six months will likely have been forgotten, by the end of the six months, what got her in trouble in the first place, so the connection between negative behavior and undesired consequence is lost. Also, a parent who has grounded a child for six months cannot ground that child again for six months, and has a lost a possible consequence. A more reasonable approach would be either to extend the length of time more slowly or, better yet, reconsider the type of consequence all together. Chances are, if the initial grounding did not change the behavior, the child does not mind being grounded. This a time for parents to get creative-perhaps withholding money would be more motivating, or reducing curfew for two weeks, or eliminating outings on Friday or Saturday night for one week.
Consequences also work better if they are known in advance. A child who know he will be fined $50 for every hour he is late for curfew is much more likely to be on time than one who finds out only after the fact. He is also less likely to argue the fee, since he was aware of it when he decided to stay out late. A child who knows the consequence before he earns it will not be happy about it, but he will be less angry and resentful, and can see better the relationship between his actions and the results of these actions.
Consequences are an important tool in shaping the behavior of adolescents. Consequences that are consistent, personalized to the adolescent, and reasonable will be most effective and are useful tools for many parents.