By sanity I'm assuming you mean serious horse's-head-in-the-refrigerator loopiness and not the sort of insanity that makes grown men construct trebuchets or think they can write novels. Also, I considered trustworthiness and honesty for that list but didn't include them because I think most people are honest and weeding out the remaining few may take time, but those are all good points.

'Sanity' made me chuckle. It's important, but it's like listing 'not a serial killer'.

Serial killers are one in a million, if that, whereas I suspect at least 1% of good hackers are too crazy to work with.

That's interesting. Can you say why you suspect that without naming names, or list some traits that would make someone too crazy to work with? Did anything specific happen at a company you can talk about?

I can't think of anything that would qualify any of the dozen or so programmers I know as crazy. It'd be interesting to know what a crazy hacker is like.

If you haven't met the 1% he's talking about... it might be you :)

It'd be arrogant to rule that possibility out, but I'm cheerful.

Especially when I have dinner arrangements with Hannibal.

Hey, wanna tag along sometime? We'd love to have a friend for dinner.

This is probably true of people in any creative field.

From what I understand it's also multiplicative. So for example if someone were both a hacker and a painter...

I murdered a lot of people; lets get rich.