I may be biased, as I was a psychology student and continue to have an interest in the study of human behaviour, but this book has genuinely influenced and helped shape my view on criminal and everyday behaviour. The authors do a great job in not only painting a picture of the therapy sessions and patients, but diving into their behaviours and how an “average” person can turn into a criminal. A lot of the time, people have an “us and them” mentality, often classifying murderers and arsonists as completely separate beings. The Devil You Know takes us down rational albeit difficult paths showing that the development of anti-social behaviours can never simply be put down to a “bad person” but that the same everyday emotions and cognitions that we feel can be interpreted, twisted and morph into the rational behind a criminal.