Throughout the ages, the multi-armed Hindu Goddess Durga has exemplified the talent of multi-tasking. Unfortunately, few of us have ten arms and three eyes. Perhaps this is why a British study conducted at King's College London University found that multi-tasking, such as allowing frequent interruptions as you work at your desk, can reduce IQ by 10 points. This is equivalent to the negative effects of sleep deprivation after heaving an all-nighter. And it’s more than double the 4-point decrease recorded in subjects after they smoked marijuana.

Researchers consider just a couple of IQ points to be a significant shift. Ten points is an enormous swing. Huge, actually. Just 20 points lower and you'd be considered mentally handicapped.

In the modern world, we are often tempted to perform many tasks at once. I am a chief offender when I'm at home, sometimes using the phone, my laptop, and my Blackberry all at once. If I’m just playing around, the T.V. might even come on. But when it comes to performing serious work, my rule is that the multitasking stops. In “Kick Ass in College” we talk, for example, about the need to avoid listening to music while studying. Sorry if I sound like a hardass but your time is precious and you are simply wasting it if you don’t study in silence. Multi-tasking like this deteriorates our ability to focus and remember, and listening to music amounts to a “task.” This means you music lovers have to study much lo-o-o-onger to master the same amount of material.

But don’t just take my word for it. "When we're multi-tasking, we don't focus our attention, so information never gets into our memory stores," says Dr. Gary Small, a memory specialist at the University of California, Los Angeles. "We just never learned the information to begin with." NBC News correspondent Dr. Bruce Hensel seconds that emotion, noting that “research shows multi-tasking uses too many parts of the brain at once… Memory and focus areas may not light up on brain maps as much. The stress also may shrink memory receptors.”

Okay, okay… I suppose you do have the occasional exception. Take US snowboarder Hannah Teter, who listened to her iPod as she won her gold medal in Turin. She says she was listening to her boyfriend’s band while doing her thing on the half-pipe. But I bet she wouldn’t have won a gold medal in Biochemistry if she listened to that crap during the big test.