I am especially inclined to believe people I have deemed credible. If my dad says it - it's true. Several professors, authors, friends, and my pastor also have that privilege. But even if people aren't all that trustworthy, I still want to accept whatever they have to share. Some would call me gullible. I have learned to temper that trait by being slow to speak regarding new information - perhaps that's why I rarely retweet anything - or respond to comments on twitter in general. I have had to train myself to think critically. Still, I want to embrace every fresh thought I find and I am more than a little bit sad when something I believe to be true turns out to be a sham (see mythbusters).
My sister is different. Whenever she sees, hears, or through some other sense encounters a new concept, she looks for confirmation. If I tell her something, she says "where did you hear that?" and demands 3 credible sources. It's worse if she thinks you're wrong. She will fight to the death to defend what she "knows" to be true.
People have often been divided into either/or groups. Those who drink Pepsi or those who drink Coke. Those who prefer the Beatles or those who prefer Elvis. Those who take the road less traveled and those who take the road more frequently traveled. Those who count and those who can't.
I submit another division - those who embrace new ideas, and those who do background checks first. We need both types of people.