From memory David was talking about Cognitive Dissonance. An excerpt from Wikipedia:
"Cognitive dissonance is a psychological term describing the uncomfortable tension that may result from having two conflicting thoughts (cognition) at the same time or engaging in behavior that conflicts with one's beliefs.
In popular usage, it can be associated with the tendency for people to resist information that they don't want to think about, because if they did it would create cognitive dissonance, and perhaps require them to act in ways that depart from their comfortable habits. They usually have at least partial awareness of the information, without having moved to full acceptance of it, and are thus in a state of denial about it."