I have been learning some very interesting things this semester. A topic we just finished in my cognitive development class is False Memory and how memories are changed/elaborated/adjusted without the person even realizing.
Piaget, who is a wide known developmental theorists has a vivid memory of a kidnapping that occurred around the age of 2. He says he can remember being in the stroller in the park and seeing the man attack the nanny. He says he always remembers vividly about the scratches and marks on the nanny's face. He accounts of how he can see the escaping the robber. The nanny after telling this thrilling tale to the parents received a reward, naturally. Years and years later the nanny confesses that this story was false!! Her and Piaget had never been attacked and she made up the whole thing! But he remembered and could picture it?!
Also in a study done by Elizabeth Loftus (not that you care who it was done by). She was able through suggestion, to convince children that they had gotten their fingers trapped in a mouse trap. She did this by asking them questions like "have you ever gotten your fingers smashed by a mouse trap?" "are you sure you've never gotten your fingers trapped?" "try to picture your fingers getting trapped" etc. After this the kids said they remembered the event!! After Loftus told them she made it up and they had not gotten their fingers trapped in a mouse trap before they refused it and said they could remember that they had!
If you ask a child a question and they give you an answer, once you re-ask the question they will sometimes give you a different answer and totally believe that it is true!!
Also due to lack of maturation of the brain children can sometimes forget who did what in memories. For instance if you ask who broke the vase, in a tone suggesting punishment, their memory may actually tell them that it was not them, even if it was.
So when you feel your child is lying to you, they may be telling you what to them is the truth.
And if you get in an argument over a memory you share with someone... it is possible that you are both right! Due to time your memories have changed so they no longer match, but to you they are correct!!
the brain is sooo interesting