What happens in vagueness

Why do people speak vaguely when they propose illicit deals? We examine the strategic use of vague speech. Participants play an economic game in which a schemer and accomplice can coordinate to take money from a mark. When a cop was watching, the schemer was more likely to send a vague message (“Some things are better left unsaid”) to the accomplice, which usually recruited the accomplice to collude. In Experiment 2, the schemer could write their own message. When the cop was watching, they wrote messages that were more vague, which again recruited the accomplice effectively.