April Fool's! We're not turning our backs on investing -- though we did fool some of you.

There's always one. Maybe she micromanages, checking in three times a day on tasks not due for another week. Maybe he's always hanging around the water cooler, talking about how fantastic his work is rather than, you know, actually doing the work. Maybe she never gets anything in on time; maybe he's constantly jostling for your position.

But before you spike that special colleague's morning coffee with correction fluid, check out the Enneagram -- a modern personality system that can tell you which of nine personality types he or she fits into. In other words, with the Enneagram, you can figure out your colleague's particular brand of crazy. And if nothing else, it'll give you something to do during your next meeting.

So what's with your co-worker, anyway?
Behold. I will now decipher the personality types of your office in relation to the Enneagram, which labels types as "Ones" through "Nines."

Ones spot the smallest error, however insignificant, and then redo the error themselves. Twos would rather hang out and talk about the way your last relationship went south than bother fixing the formulas in the spreadsheet. Threes want you to know that if sales went up 43% last quarter, it was all them.

Fours need you to understand how they feel about the project ... and about Sally in accounting ... and about yesterday's lunch. Fives don't want to chat over the water cooler; they'd rather read the latest issue of Scientific American. Sixes will think of every single thing that could possibly go wrong with this plan, and then they'll worry that you're secretly criticizing them.

Sevens have 18 ideas all at once, and they want to try all of them. And don't you dare tell them that some of those ideas would require rewriting the Second Law of Thermodynamics. You know, if those ideas were actually going to happen. Eights tell it like it is, no matter how brutal it sounds. And by the way, don't even think about crossing them. Nines are fine. Really, they're fine. And if you could just leave them alone and maybe move out of the patch of sunlight you're blocking? Yeah, that would be awesome.

Now what?
Need just a bit more information? Take the free test at The Enneagram Institute or read more in-depth descriptions of the types. Because nodding knowingly and saying "well, you are a Seven" is so much more fun than stewing.

Find out why The Motley Fool is taking a break from investing.

Julie Clarenbach would really like that patch of sunlight now. She owns no shares of the Enneagram, although she's got a controlling stake in Six. The Fool's disclosure policy says "it's the best I can do."