@done4good
You misunderstand.
While we are agreeing that the days and/or years the person remaining in denial are not periods of "cognitive dissonance," I was stating that some others have made the mistake of saying that these long periods of being in denial are "cognitive dissonance" in themselves.
Long periods of denial can be caused by cognitive dissonance, but they aren't the same thing.
As for my pastor friend, she did not dig in deeper, she let go of it as soon as she had a moment to herself to look at the matter. The days following 9/11 were not days of "refusal to let go" as she compartmentalized the situation to avoid confronting the cognitive dissonance. But after about two weeks she had time to herself, discussed it with friends like me, and discarded these views as illogical when she could. Before it was not possible.
Many people had to compartmentalize to get through those days. Rescue workers at the scenes of destruction had to compartmentalize their fears and frustration and just work as if on "automatic" like my pastor friend. Most didn't have the luxury of stopping tand dealing with their situation. Some stayed in this mode for quite some time because that is what they had to do.
This is not the same as denial as one does in an ideology when faced with facts that conflict with one's thoughts. These people were moved by a sense of duty to complete their jobs which they vowed to perform. Rescue workers consisted of police, firefighters, and others like clergy who had to do their jobs without thinking of themselves.
My friend had to selflessly think of others for days before stopping to consider her own self and struggles. This was not "digging in deeper." This was done out of her duty to serve the public. What Witnesses do is a selfish choice to avoid dealing with the cognitive dissonance. What my friend did was very different.
But to clarify, my statements were mainly directed at the way others have been using the term. Your use of "collective cognitive dissonance" implied that an ideology thrives on this, wherein the reality is that they thrive because they don't deal with it or take steps to avoid situations that cause the dissonance in the first place. That made me feel I should add something lest someone make the mistake as to what this dissonance was.