But I've been thinking about personality types lately and which ones fit into projects and make good developers. Many years ago my brother, who is a WWII history guy, told me about Kurt von Hammerstein-Equord's method for classifying his officers. I don't usually take the advice of nazi generals, but this method seems to have resonated with me and every time I tell someone else about it they seem to smile and draw some value.
Basically he had four defining characteristics: smart, stupid, lazy, industrious: "I divide my officers into four classes; the clever, the lazy, the industrious, and the stupid. Most often two of these qualities come together. The officers who are clever and industrious are fitted for the highest staff appointments. Those who are stupid and lazy make up around 90% of every army in the world, and they can be used for routine work. The man who is clever and lazy however is for the very highest command; he has the temperament and nerves to deal with all situations. But whoever is stupid and industrious is a menace and must be removed immediately!"
I think this applies to programmers pretty closely. Regard the quadrant below:
Programmers who are stupid and lazy are all over the place. In large projects there is room for these types as there are always jobs for them to do. More importantly, they aren't dangerous as they'll be wasting time reading 4chan instead of injecting bugs. These are the types that are the reason why project managers micromanage "What do you mean you spent 8 hours editing a label on the welcome screen?"
Next are the smart and industrious programmers. I thought these were the prized employees, the ones you really want. Smart and hard-working is a good thing right? Yes, that's right these are the guys and ladies who will identify the problem and work hard until it's complete. Boy scouts of the programming world.
Closely related are the smart and lazy programmers. These are the guys who really waste time and mess around, but are able to re-use someone else's API to do the work better than spending 20 hours writing it from scratch. The trick here though is to make that they aren't too lazy. I mean you want them coming into work and all.
Finally, you have the stupid and industrious programmers. These are dangerous. These will ruin your project and make you miss dates. "I spent all week-end re-writing the login module so it will only use digital certificates instead of userid and password." or "I wrote a wonder configurator to set the properties in the project. But the configurator only works on a JVM we don't use and there's no other way to configure the project." Stuff like this will make the smart/lazies, stupid/lazies and smart/industrious work overtime to get back to zero.
Update 2009.06.04 2154EDT: As pointed out below by thecodist, Hammerstein-Equord, although in the Nazi army, was actually against the Nazi party, hated Hitler and spent most of his later life trying to stop the Nazis.