In movies, people who drive expensive cars are usually jerks. That's often designed to make us root for the down-to-earth, middle-class hero, but data suggests that there may be some truth to the cliche.
Numerous studies have shown that a person's financial status can predict her ability to empathize with others. Specifically, people with higher incomes have shown poorer empathy skills than people with lower incomes.
One such study involved showing subjects photos of other people's faces. On the whole, participants with lower reported incomes did a better job of assessing the emotional states of the people in the photos (e.g. whether they were happy, sad, anxious, etc.) than people with higher reported incomes.
That's in keeping with another series of seven studies that showed wealthier people behaving more unethically (and hence, un-empathetically) than poorer people. For example, they were more prone to lie during negotiations, cheat in order to win prizes, and encourage unethical behavior in the workplace. Which sounds a little familiar, no?
Two of those seven studies were conducted by observing stop-sign intersections. What researchers discovered was that drivers of mass-market cars were significantly more likely to wait their turn, and they were also more likely to yield to pedestrians. Drivers of luxury vehicles, however, were more likely to cut off other drivers and ignore pedestrians--which wasn't just rude, but also a violation of the law.
Of course, the studies aren't without their flaws. The most glaring problem is that researchers couldn't really know about the passing drivers' household incomes. Without that data, it's impossible to correlate higher income with a lack of empathy.
All that can really be said is that people who drive mass-market vehicles are more likely to be kind to strangers--presumably even wealthy people like Julia Roberts and Bradley Cooper, who both drive the Toyota Prius.
Conversely, people who drive luxury vehicles--even those who can't truly afford them, which is most people--are less likely to be kind. Other studies suggest that this lack of empathy can be related to greed, or prioritizing material goods over people.
These are massive generalizations, of course, and we're sure that all of you who drive premium rides are just swell. And more than a few still driving K-cars are probably schmucks.