<p>Does exposure to organised-crime violence shape the honesty of young residents living in affected areas? We investigated this question through an online experiment featuring 30 coin flips among residents of Campania (Southern Italy). Participants were recruited from areas either exposed or not exposed to organised-crime violence. They could cheat by misreporting coin-flip outcomes or skipping flips altogether. Since 30 coin flips require time, finishing too quickly indicated potential cheating on task completion. We recorded participants’ completion times and used a mixture model to classify them as “Fast” or “Slow”. “Fast” participants lied more frequently about coin-toss outcomes and cheated more on task completion. Notably, dishonest Fast-types were more prevalent in violence-exposed areas, suggesting that living amid organised crime lowers the threshold for dishonest behaviour, consistent with a “Neighbourhood Effect”. This evidence calls for policies addressing the social roots of dishonesty—especially in crime-affected areas—through education, transparency, and peer incentives that foster accountability.</p>