One of the things I noticed soon after becoming an adoptive parent to older kids is that it appears that they can't tell the truth no matter what.
Having parented them for ten years now, I ahve noticed that sometimes lying isn't lying as we know it. We use the word "liar" to describe someone who intentionally deceives. Sometimes I think we need to use different words.
For children who have developmental disabilities or have organic brain damage due to pre-natal exposure to drugs or alcohol, they really cannot remember. It seems almost impossible for those of us with "regular" brains to beleive, but they really do not remember things. Even things that happened just a few minutes before don't pop into mind when they are asked.
The challenges, as these kids get older, is that they realize that they are SUPPOSED to remember. The response, "I don't know" when the question, "Where were you this morning" is asked they realize is not acceptable. They might remember a little bit, but they don't remember it all. And so they fill in the details. And sometimes what they come up with is so rediculous that we can't believe it.
So, when we here a story our fully functioning brains send messages to our appropriately functioning emotions like, "How stupid do you think I am to believe a story like that?", or "If you're going to lie, at least make it believable" or, "I am going to so ground you and teach you to become an honest person?". And we become angry and it doesn't take long for us to really work ourselves into a fury.
Another piece of "lying" is self-protection. If as a small child I learn that if I admit to wrong doing, I will be beat nearly unconscious, my initial instinct is to deny any involvement. It's a learned behavior and very hard to unlearn because it is at the very center of the individuals desire to keep themselves physically safe.
Rethinking "lying" as parents, will keep us more sane, more compassionate, and more stable. Because the idea behind lying is the concept of deception, which may not be the issue at all.