Most parents are overprotective in guarding their children, some even designate areas for their kids and so many do's and don't .
And whenever a child goes against this rules in other to avoid being spanked they do anything most at times lie, just to avoid their parents rot. As a result of this making them lie so often.

once you become overprotective and don't give your child freedom to explore or express himself he will surely lie to avoid your beam .
again you're harsh and too judgemental of your child's work, words, friends, games, attitude and leisure that child will be under EXTREME pressure, then LYING becomes his second nature even if he has genuine intentions and purpose because he'll feel you won't approve or you don't trust his abilities!