Sojha beta, varna Gabbar aa jayega

I have a maid helping me out with Vidur and other chores at home. My maid uses fear to try and ensure that Vidur listens to her. She says (in tamil) "Don't go there! There is a cat there. Shall I ask it to come and bite you?" or "Squeak! Squeak! Rat! Rat! Don't go there Vidur!" Haven't you heard similar instances before? Some age old fear mechanisms are:

• Will you eat or shall I call the policeman? He will take you away.
• Don't touch that else aunty/uncle will shout at/hit you!
• Don't touch that else I will never take you out/bring you here.
• Go to sleep now otherwise the monster/ghost will come and eat you!

Why do we use these fear mechanisms? Does simple, plain logic not work? I bet it doesn't! When children are being naughty, they typically know that they are not supposed to be doing it. You can see the mischievous look in their eyes. But I think a stern 'no' would work. Kids are very perceptive and pick up tones and facial expressions really early. I guess I will know soon if this technique will work better than the fear technique. Will share...