When Nigerian prince scam spam hits our inboxes, most of us know to politely decline requests for assistance. One might wonder why scammers don’t come up with something a bit more believable. But according to a new paper (pdf) by Cormac Hurley of Microsoft Research, the email’s overt scaminess helps identify the biggest suckers. Psychology professor Daniel Simons, who wrote about the phenomenon in the Wall Street Journal, explains.