I tend to agree with Terry about people on average. We might be somewhat exceptional in this sense having left a group like the WTS. I went from dedicated JW to a skeptical secular atheist myself, so some people can make dramatic changes. But I've also met some ex-Witnesses that haven't strayed far at all. (I'm new in here, so I can't comment about members of this board)
I have a rather lengthy bit of personal philosophy to go with this, but it's too long and no one will read it. But I think most people form a general world view fairly early in life and tend to stick with it unless something totally earth shattering occurs. It's easier for us to take every bit of new evidence or information and try to fit it into that worldview instead of adjusting our worldview to fit the evidence. So we tend to rationalize things without realizing it, or simply rejecting the things that don't fit.
I could give examples, but don't want to step on anyone's toes. :-) This seems like a pretty varied collection of folks.
IsaacJ