The key insight that I got from this @copyblogger post is that, regardless of our "resting" personality type, we are different when doing different activities.
My Myers-Briggs type pegs me as generally an "Environmental" type. However, when I'm researching, I'm generally "Fantastical" (and I'm not just complimenting myself). When I'm writing I'm getting my "Structural" on.
In short, we can't treat people as one personality type. We change from channel to channel.
What are the four personality types when people are solving the problems your business solves?