It served nobly, though it was not a Plymouth Valiant. It took me to new places, though it was not a Ford Explorer. I parked it under a tree, though it was not a Toyota Sequoia. (The tree was a maple.) It was the last car I had bought, a 1992 Honda Civic. It even had an air bag—for the driver. But the years had passed it by: my passengers wanted air bags, too, and I conceded that it was time for a new car.

Also, the air conditioner has been busted for something like eight years. I frequently considered rectifying the situation, but it seemed like a poor investment to throw $1,000 into a car with a book value of, well, nothing. The economics of such a repair said that I wouldn’t be making an air-conditioned car, I’d be making a portable air conditioner.

So I entered the automobile market. Which meant interacting with one of the most lampooned and reviled figures in the history of American commerce: the car salesman. Fortunately, I walked into showrooms armed. Because I had read Scientific American’s February 2001 article by social psychologist Robert B. Cialdini, “The Science of Persuasion.” The piece outlines the basic methods to change someone’s mind or to get the person to act a certain way. And knowing about these methods can offer immunity to the one being persuaded—aka the mark or the chump.

For example, when the chatty salesman at the first dealership discovered, or invented, that we had similar backgrounds, I knew that he was trying to establish rapport, because we are much more likely to do something for somebody we like. It didn’t work.

When he called a few days later to tell me that the car I had looked at was available at a reduced price “today only,” I knew that he was using the scarcity tactic—we’re more enticed to grab something when its availability is limited. This approach might have paid off if the car he was selling wasn’t also limited in its right-side sight lines. At the “today only” price, it was an attractive option if I committed to making only left turns.

The salesman at a second dealership sat next to me on a test drive. As we passed a gas station, he said, “Whew, look at those prices.” I realized that this remark was a reminder that the car would use less high-cost fuel. As social creatures, humans are hardwired to reciprocate when someone does something for us. And he was allegedly doing me the favor of saving money on gas in the future, making me more likely to do him the favor of buying his car in the present. His theoretical generosity was sadly mitigated by the car being a kidney-rattling tin can.

At the third dealership, I encountered a laid-back salesman whose style actually did make me like him, whether that was his strategy or not. I also liked his car and bought it. But when I went to take delivery, I was disappointed to find that the brand-new car had a long and ugly scratch on the hood. My salesman was out that day, and I was told I would have to talk to the business manager. He sat on a platform two feet above the showroom floor. This move, of course, is designed to make him appear to be an authority figure—all he needed was the black robe and gavel—because we are inherently moved to believe in and submit to authority.

Again, my knowledge offered me some immunity. When I told the business manager that I would not be accepting the car until the scratch was dealt with, he invoked the rules of reciprocity and scarcity: “You know,” he said, “we worked really hard to get you this car.” I then countered with my own scarcity move—I pulled the check out of my pocket and said, “Well, I worked really hard for this money. Call me when the car is perfect.”

Which they did the very next day. Of course, we both know that I didn’t really work hard. But that can be our little secret. Because we’re friends, right?