Codes of the Underworld
How do criminals (notoriously an untrustworthy population) convince other criminals to trust them?
Why do real-life criminals adopt language and symbols from gangster movies?
Why is violence more common in prisons with a high inmate turnover?
Absolutely fascinating throughout, and relevant even for those not considering a career switch to the underworld. One key theme: expanding the idea of communication beyond language to include actions, particularly “honest signals,” that is, actions which are relatively cheap for an honest communicator to send and expensive for a dishonest communicator.
Highly recommended: Codes of the Underworld: How Criminals Communicate, by Diego Gambetta