A few years ago, the comic strip Dilbert featured a story line in which Dilbert was experimenting with a miniature computer. The screen was embedded in his eyeglasses; the keyboard in attachments to his fingertips. As he walked along the street wiggling his fingers—presumably working on his computer—he ran into a fellow acting the same way. I don't remember the punch line exactly (you'll understand why presently), but it went something like this: Dilbert asks the other person if he's also an engineer. The reply: No, I'm an idiot.

Turns out there's more truth in that than anyone guessed. It seems that science now has documented what most of us have long suspected—that e-mail, instant messaging and the like so distract us that they quite literally diminish intelligence.

According to news reports, studies conducted by researchers at King's College in London have found that extensive e-mailing and text messaging reduce mental capacity. In trials involving more than 1,000 adults, e-mailers suffered a drop in IQ of a full 10 percent—about twice that of marijuana users, and without the kick. The idea is that technology that constantly demands attention erodes mental discipline and concentration.

I think we all know people who are living evidence of that. I personally have to look no farther than the mirror. I have one colleague who's so tied to his cell phone that even if we're in the same room, I'm better off calling him in order to get his attention. And how often these days do people e-mail co-workers in the next office or cubicle?

It's not just the amount of time consumed by e-mail—although the volume of messages alone makes it hard to parse what arrives each day. What's even worse, to my admittedly addled mind, is that e-mail creates an expectation that I'll be able to complete a task in the same 30 seconds or so it takes to scan an e-mail message.

So should we just unplug all the devices? No, it's too late for that. See, the insidious thing is we need that e-mail. We want that e-mail. We can't handle a day without it. Logging off would be tougher than quitting smoking. (Will there someday be an E-mail Anonymous? Or maybe counseling to help wean retirees off their Blackberries? But I digress—it's hard to stick to one topic for long.)

When I started this missive, I had some ideas on how we might mitigate this problem, but 500 words later, I forgot what they were. Let me think. … Hold on a minute, I just need to answer this message first.