Because I said so

Here is a brief article sent to me by someone from this site--usually packed with useful and practical information. In this case, however, I would disagree. The article identifies 10 instances when it's o.k. to say "because I said so" in answer to one or more of a child's questions. Generally, I would argue that "because I said so" is not so much an answer to the child's question as an expression of frustration on the part of the parent. It doesn't answer the child's question; rather, it tells the child to "shut up," "go away," "your questions are annoying me". It's a disconfirming strategy. In addition, saying "because I said so" misses the great opportunity for the parent to teach the child logical reasoning--for example, that certain things are related--like not getting enough sleep and poor performance on the field or in the test. It also discourages the child from asking questions; the child will soon learn that his or her questions are not welcomed and that life is a lot better when you don't ask questions--an outcome we really don't want to encourage.
     This is not to say that some questions aren't annoying and frustrating; many are. But, "answering" with "because I said so" should not be a recommended solution.

http://www.nannyjobs.org/blog/10-times-because-i-said-so-is-appropriate-kids/