This was a pretty interesting finding. It says a lot about how sometimes people behave (voting, working, local civic activism) against their own best interests.
Past research has shown that people often act against their best interests to satisfy visceral emotions and fears. In these cases, we don’t realize we are acting against our own interests. For example, working class people are often against taxing the rich. This seems against their interests. But there is a subconscious feeling that if we are against rich people we are concluding that we will never be one of them. It’s like saying they are one group and we are a separate group and you can’t go from one to the other. It’s an odd form of loss aversion. There is a visceral feeling like if we support taxes on the rich we are admitting defeat in our own lives. Not everyone feels this way or votes this way, but it is enough to shift a few key elections now and again.
The same thing happens with the minimum wage. There is an odd drop in support for people who make just above the minimum. Unconsciously (or maybe even consciously) they feel like if the minimum wage gets raised to what they are already making, then all the people they used to be "ahead" of catch up and now they are in last place too.
This study added a nuance. You can imagine from my title what the basic finding is. People have basic competitive instincts where we want to win, want to get ahead, would rather be in second place than third place. But there is a stronger aversion to last place. We will do almost anything not to be last, even if it means acting against our own self interest as long as it puts someone else in last place.
This is an oversimplification , but basically they gave random people all different amounts of money. The requirement was that they had to give some of it to someone else. Most of the people gave money to people who had less (we are all somewhat altruistic at heart). The only exception was the people who had the second least. They refused to give money to the person at the bottom because then they would be the person at the bottom. Even though it was random – it wasn’t any kind of statement about their abilities or talent – they still couldn’t bring themselves to do anything that would put themselves into last place.