Forewarning reduces fraud susceptibility in vulnerable consumers.

Telemarketing fraud is pervasive and older consumers are disproportionally targeted. Given laboratory research showing that forewarning can effectively counter influence appeals, we conducted a field experiment to test whether forewarning could protect people who had been victimized in the past. A research assistant with prior experience as a telemarketer pitched a mock scam two or four weeks after participants were warned about the same scam or an entirely different scam. Both warnings reduced unequivocal acceptance of the mock scam although outright refusals (as opposed to expressions of skepticism) were more frequent with the warning than the warning. The warning, but not the warning, lost effectiveness over time. Findings demonstrate that social psychological research can inform effective protection strategies against telemarketing fraud.