How predictable are people on a scale from 1-10?

10 if you're paying attention. Not hard to do.

I seem to spend my life studying people, it's become second nature to me and I can read people very easily. So much so that I've been nicknamed The Witch by my family...

People aren't predictable. I'm unpredictable, man. Unpredictable like the wind. You'll never know if I'll go to the movies, or punch you in the nuts. yep, I've been known to do that. My parole officer knows that all to well. So does his wife.

Hmm. It really does depend. If I was intentionally trying to do something that involved people not predicting what it is I am doing, I would have to say between three and one.
Some times I am a little "unpredictable" on here due to sometimes setting up little "traps" in debates to trap people in words, but I very rarely do that.
In reality, I would say three to one. The things I have done people don't even thought I have done or would ever do.
On IsItNormal, I am probably very predictable when I'm not trying to be unpredictable. I am more myself and honest on here than I am in real life, so it's a bit obvious people on here would know me and be able to predict a lot of what I will do on here.

As a whole? People are pretty predictable.
As individuals, if you know enough about why people do what they do (which is mainly rooted in ego and preservation of self worth) people can be extremely easy to predict and at the same time, there are people that have more on their mind than their self worth, ego, and need to survive and feel important. In such a case, they're not entirely predictable if you don't know them well enough.

I would say en masse they are a 10, but individually I can't tell at all unless I've known them a long time.

honestly it depends on where you live at.

10. I watch people constantly.

It depends on the person.

What happens if you're wrong?

yep, its a loaded question.

If it's people as a group, they are usually quite predictable.
If it's an individual going by their normal routine, they will also be rather predictable.

If it's between 2 people in a competitive way(that is, one is trying to predict and the other trying not to be predicted), there's a lot of factors:
First of all, the matter at hand. A chess novice may try to GUESS what move a pro would make in any one situation, but to be able to predict, he'd have to have a more wholesame understanding of the materia.
Secondly, acting unexpectedly. Even random. Makes things pretty damn hard to predict, especially if you throw in randomness while following a grander plan masked by it.

Damn, to anybody that picked a 10, you should go play poker. It takes less experience to understand over pure strategic games, and it's all about predicting what people will do. If you can read them like a book, you should be pretty capable of pinpointing exactly when they are bluffing, when they are unsure, or when they have a good hand.

Individuals or people as a whole?