Normally I review a book after the first time I finish reading it, but this one is a little different. I’ve read Mistakes were made (but not by me) multiple times in the ~10 years that it has lived on my bookshelf, and I can recommend it almost wholeheartedly. Its writing is clear and accessible, the example and stories involved are chosen well and discussed with compassion, and the sourcing appears sound. Plus, the ideas it discusses are certainly relevant right now!
“These metaphors of memory are popular, reassuring, and wrong. Memories are not buried somewhere in the brain, as if they were bones at an archeological site; nor can we uproot them, as if they were radishes; nor, when they are dug up, are they perfectly preserved. We do not remember everything that happens to us; we select only highlights”.
The book also sets an appropriate scope, as it does not proclaim that its central subject of dissonance theory and self-justification is the sole cause of the world’s ills nor that understanding and correcting our bias towards self-justification will solve all problems. Instead, the authors more reasonably claim that the knowledge of cognitive dissonance will “make sense of dozens of the things that people do that would otherwise seem unfathomable and crazy” and that “understanding is the first step towards finding solutions that lead to change and redemption”. For me, this more measured approach to its potential value makes the book more trustworthy.
However, the main flaw this book has is the field it come from. As a social psychology book written in 2007, this book has more potential than most to be built on flawed foundations. I’m not saying “older research is bad”; I’m referring here to the way that the replication crisis has created a large, justified, doubt in psychology research findings, especially in social psychology findings.
Because the authors of this book have a strong pedigree in this field – one author is the direct student of Leon Festinger, the influential cognitive psychologist who founded the theory of cognitive dissonance in 1957 – this book is likely to have been written extremely carefully, as poor communication of the research would be disrespectful to the author’s mentor. On the other hand, according to the very theory this book discusses, that closeness would make it even more difficult for the authors to identify any flaws in the theory or in research supporting the theory.
During my latest re-read, I have seen a few sentences where I doubt the references cited at the time will still stand. For example, the phrase “scientists have even tracked [a bias named] imagination inflation into the brain, using functional MRI to show how it works at a neural level” has my suspicion. That’s partly because its a surprisingly un-nuanced summary when compared to the caveats and nuances provided in other summaries in the book. However it’s mostly because, while all fMRI studies have the potential for error due to how the data must be developed and interpreted rather than just observed, fMRI studies done before the Dead Salmon Incident of 2009 are even more likely to have mistaken noise for signal and to have therefore made claims that can’t be replicated.
“Over time, as the self-serving distortions of memory kick in and we forget or distort past events, we may come to believe our own lies, little by little. We know we did something wrong, but gradually we begin to think it wasn’t all our fault, and after all the situation was complex. We start underestimating our own responsibility, whittling away at it until it is a mere shadow of its former hulking self. Before long, we have persuaded ourselves, believing privately what we originally said publicly.”
The book covers how dissonance theory can be part of many situations, both individual (relationships, memories) and societal (policing, politics). While it dives in to heavy topics, including the repressed memory scandal and forced police confessions, it does so without overly dramatising its descriptions, or caricaturing the characters. Many of the examples of cognitive dissonance provided in the book come from US political figures, as their misdeeds are normally more public and more well-documented than those of regular people. The examples felt fairly tame by the current-day standards of politician behaviour, which made me wonder how this book would be different if it was updated for 2025. As a UK resident, I would be interested in explanations of how cognitive dissonance and self-justification could be in play for many Trump supporters, especially those who are already marginalised and who therefore seem to be putting their own stability at risk by supporting the US Republican Party.
The final chapter gives examples of people who were able to reverse course from self-justification and fully commit to establishing the truth and the responsibility of their situations. The authors don’t claim that this is an easy thing to do, but also do not cordon it off as something only achievable by saints. This framing, which is optimistic but not unrealistically so, works well and means the end of the book feels like a sufficient explanation and ending.
“Becoming aware that we are in a state of dissonance can help us make sharper, smarter, conscious choices instead of letting automatic, self-protective mechanisms resolve our discomfort in our favor. Suppose your unpleasant, aggressive coworker has just made an innovative suggestion at a group meeting. You could say to yourself, “An ignorant jerk like her could not possibly have a good idea about anything,” and shoot her suggestion down in flames./…/ Or you could give yourself some breathing room and ask: “Could the idea be a smart one? How would I feel about it if it came from my ally on this project?” If it is a good idea, you might support your coworker’s proposal even if you continue to dislike her as a person.”
Ultimately the advice for how to reduce this form of bias is similar to the advice that already exists for reducing other forms of bias. The most important elements are being aware of what factors and situations provoke cognitive dissonance for you, being able to challenge your initial reactions to identify if they are biased, and being able to admit when you have already started down the slippery slope of rewriting memories or events. These general points stay sound even if individual studies supporting them are flawed.
Overall, Mistakes were made… is a well-written work of pop-psychology that definitely can be enjoyably read rather than just referenced. It delivers a persuasive argument about the effects and power of self-justification, using well-chosen examples. Its general advice for reducing the effects of self-justification is sound, and its conclusions are sensible. I would recommend reading it, then supplementing it with more recent information and studies to confirm its overall soundness.