It's a form of coercive parenting, based on often-unstated threats of 'what might happen' if mom gets to 3.
You give an order, and if the child doesn't obey in whatever amount of time you arbitrarily decide qualifies as obedience, you start counting at whatever speed you like. When you get to three, something horrible is supposed to happen. Young children are just afraid --unless they're me in which case the curiosity will not let up until I find out, and I was always perfectly willing to accept a pounding to know, and then carry on doing exactly what I had already been doing-- but older kids catch on and it (like every other form of threat, bullying or controlling authoritarian parenting) stops working completely.
It is just as effective at teaching children to be mindlessly rebellious, forgetful, non-compliant, oppositional and self-destructive as any other form of autocratic parenting.
at 9:15 PM on Dec. 16, 2010