A funny thing happened last weekend linked to this question of cognitive dissonance that I'm interested in. We ended up watching one of those ITV adaptations of an Agatha Christie novel with David Suchet as Poirot. I say ended up watching, actually it's become a regular fixture (hey, we're new parents, our social life is not what it was). This particular adaptation was of One, Two Buckle My Shoe which, like quite a few Agatha Christie plots, involves some character not being who they appear to be. Basically, early on we are introduced to the character of Mabelle Sainsbury Seale. Later, one of the other characters assumes her identity in order to help carry out a murder.
The thing is that in the TV adaption it should have been obvious that this is what happened (I haven't read the book so I don't know if it is also the case in the original). You see the actress playing the 'real' Mabelle a couple of times. Then later you also see the fake Mabelle. The strange thing was that when I watched the programme at one level I clocked this. In a scene where Poirot (who never sees the real Mabelle alive) bumps into the fake Mabelle, I thought to myself 'that doesn't look like the same actress'. And in fact they were really quite different. However, because at that time the course of the plot wasn't clear, and because she kept being referred to by other characters as if she were the real Mabelle, I started to convince myself that actually maybe it had been the same actress.
This, I humbly submit, was an attempt to reduce the dissonance between two ideas - 1. "that is a different actress" and 2. "everyone is referring to her as if it is the same character". In attempting to do address this I (subconsciously) decided to downplay the evidence of my own eyes in favour of what others had said.
Subsequently it became clear that were indeed a real Mabelle and a fake one, and all along I had an uneasy feeling about the identity of the person that Poirot met. So the dissonance was never eliminated. But I did go a long way to ignoring what I had actually seen in favour of what others had said about the same event. Now it strikes me that if I can pull this kind of trick on my own mind in respect of the entirely trivial matter of watching a TV programme, then this may affect my decisions much more strongly in others areas (especially where there isn't any physical evidence). And actually when I think about it I can see attempts to reduce dissonance in lots of areas of my life.
Equally I think I see it a bit in the bit of the world I inhabit. There is IMO a tendency to take what a lot of organisations say at face value (particularly if you are paying them a large fee). If, for example, there is evidence to suggest that Organisation X's behaviour isn't quite in line with the way that they promote themselves to the market, I suspect the tendency on the part of those that employ that organisation will be to downplay the evidence. And indeed some of the conversations I have had with trustees justifying decisions made by their fund manager would seem to bear this out.
There is no answer to this. And, as Tavris and Aronson point out, actually the reduction of dissonance through self-justification (like many heuristics) enables us to make decisions quickly and stick with them. This is not unimportant. But equally we need to be constantly aware that attempts to reduce dissonance may result in the suppression of useful information that might be used to solve difficult problems, be they a fictional murder, or ineffective organisational relationships.