If the answer to either of these questions (or ones similar) is yes, you’d probably choose not to cross the street when you might have done so if the car were a cute VW Bug being driven by a nun. The choice to cross isn’t just influenced by the physics of velocity; trust plays a role.

To relate that to social class, consider this experiment. You’re standing on a corner in downtown San Francisco. It’s a four-way stop, meaning cars are supposed to pause before entering the intersection. As you’re sipping your latte, you look to your left before stepping off the curb. The car approaching is a shiny BMW. Do you cross? How about if it’s a Ford Fusion? The model of trust I’ve been describing suggests you might want to pause if it’s the BMW. There’s really only one way to tell, though. You’ve got to put yourself out there. And that’s just what Paul Piff and colleagues from the University of California at Berkeley did.

As cars approached this busy intersection in San Francisco, a researcher would enter the crosswalk. Unbeknownst to drivers, he also noted the make of their car and their perceived age and gender. The main datum for each car was whether the driver paused to let the researcher cross at the stop sign (as is required by the California Vehicle Code) or sped up to cut him off and thereby proceed more quickly toward the driver’s goals. Paul and colleagues divided drivers into five SES categories based on their cars—think Hyundais on one end and Ferraris on the other. The results were quite remarkable.

At the lowest end of the class gradient, every single driver stopped to let the pedestrian entering the crosswalk continue on his way. Midway up the class ladder, about 30 percent of drivers broke the law and cut off the pedestrian so that they could keep going. At the upper end of SES, almost 50 percent of drivers broke the law to put their own needs first. At the most basic level, these findings offer a provocative warning. When you’re vulnerable, upper-class individuals are more likely to disregard the trust you place in them if doing so furthers their own ends.

That might seem hyperbolic. After all, we’re simply talking impersonal interactions at traffic intersections. Fair enough. If the data ended there, I’d agree there might not be much to it. But it doesn’t end there. Suspecting their view of the upper-class’ trustworthiness—or lack thereof—was correct, Piff’s team began a multi-pronged investigation that examined class-based effects both on a willingness to trust others and on trustworthy behavior itself. In all the experiments, they first divided individuals into distinct class levels based on typical measures of SES and then exposed them to different situations. What follows is a sampling.

One experiment was presented as an investigation of negotiation tactics. The participants—here members of the upper- or lower-class—were told that they would play the role of an employer negotiating a salary with a job candidate. These “employers” were given a lot of information about the job (e.g., salary ranges, details about responsibilities), but one piece was central to the researchers concerns: The job was scheduled to be eliminated in six months. As the participants reviewed the file of the job candidate they were to interview, it became clear that he was looking for a long-term job and wouldn’t consider a position unless it was likely to provide at least two years of employment. The “employers” then produced a written script of how they would describe the position to the job-seeker.