How con artists use psychology to work

From Paul J. Zak’s “How to Run a Con” (Psychology Today: 13 November 2008):

When I was in high school, I took a job at an ARCO gas station on the outskirts of Santa Barbara, California. At the time, I drove a 1967 Mustang hotrod and thought I might pick up some tips and cheap parts by working around cars after school. You see a lot of interesting things working the night shift in a sketchy neighborhood. I constantly saw people making bad decisions: drunk drivers, gang members, unhappy cops, and con men. In fact, I was the victim of a classic con called “The Pigeon Drop.” If we humans have such big brains, how can we get conned?

Here’s what happened to me. One slow Sunday afternoon, a man comes out of the restroom with a pearl necklace in his hand. “Found it on the bathroom floor” he says. He followed with “Geez, looks nice-I wonder who lost it?” Just then, the gas station’s phone rings and a man asked if anyone found a pearl necklace that he had purchased as a gift for his wife. He offers a $200 reward for the necklace’s return. I tell him that a customer found it. “OK” he says, “I’ll be there in 30 minutes.” I give him the ARCO address and he gives me his phone number. The man who found the necklace hears all this but tells me he is running late for a job interview and cannot wait for the other man to arrive.

Huum, what to do? The man with the necklace said “Why don’t I give you the necklace and we split the reward?” The greed-o-meter goes off in my head, suppressing all rational thought. “Yeah, you give me the necklace to hold and I’ll give you $100” I suggest. He agrees. Since high school kids working at gas stations don’t have $100, I take money out of the cash drawer to complete the transaction.

You can guess the rest. The man with the lost necklace doesn’t come and never answers my many calls. After about an hour, I call the police. The “pearl” necklace was a two dollar fake and the number I was calling went to a pay phone nearby. I had to fess up to my boss and pay back the money with my next paycheck.

Why did this con work? Let’s do some neuroscience. While the primary motivator from my perspective was greed, the pigeon drop cleverly engages THOMAS (The Human Oxytocin Mediated Attachment System). … THOMAS is a powerful brain circuit that releases the neurochemical oxytocin when we are trusted and induces a desire to reciprocate the trust we have been shown–even with strangers.

The key to a con is not that you trust the conman, but that he shows he trusts you. Conmen ply their trade by appearing fragile or needing help, by seeming vulnerable. Because of THOMAS, the human brain makes us feel good when we help others–this is the basis for attachment to family and friends and cooperation with strangers. “I need your help” is a potent stimulus for action.