In their book Sway, Ori and Rom Brafman tell about a test that was conducted at a college. They said the teacher couldn't make it, but they had a guest instructor. Half the students were given a brief bio that included the statement that the instructor was competent, even though he was considered to be cold by some. The other bio was given to half the students that had all the same information, except it said that the professors was said to be warm in personality.
After class, they asked students to evaluate the prof. The students who had the bio that said he was cold indicated that such was the case; the half with the bio that said he had a warm personality indicated that. [source: "Sway," by Ori and Rom Brafman, pp. 72-73.