Lies

When do kids learn to lie? Is it just an ability that's hardwired in our brains? Does it just spurn from an active imagination?

Maggie: *cry, scream* Owie smacked me!!!
Mom: Owen, did you smack Maggie?
Owen: Nope.
Maggie: Yes! Owie smacked me on my back
Mom (after examining Maggie's back): Owen, did you smack your sister?
Owen: Nope-y.
Mom: Then how did she get this mark on her back?
Owen: Mae mae hit a deer with her truck.

I'd have to give him bonus points for creativity, but he's still got a way to go on believability.