As economic inequality in the United States continues to increase, a new study offers some discouraging news for anyone expecting the rich to spontaneously help those who have less.

In a series of experiments, a team of researchers at UC Berkeley found that people of lower socioeconomic status are actually more altruistic than those higher on the economic ladder.

In one of these experiments, the researchers, led by doctoral student Paul Piff, gave participants the opportunity to share $10 with an anonymous stranger. A few days earlier, the participants had all filled out a questionnaire in which they reported their socioeconomic status. The results showed that people who had placed themselves lower on the social scale were actually more generous than upper class participants were.

That finding is consistent with national survey results showing that lower-income people donate a greater percentage of their income to charity than upper-income people do.

A second experiment built on this finding, suggesting that there’s something about the specific psychological experience of having less that induces people to give more. Piff and his colleagues, including Greater Good Science Center Faculty Dacher Keltner, had participants engage in an exercise that made them feel like they were either of higher or lower status. Then the participants had to say how they thought people should divide up their annual income—on food, recreation, charitable donations, or other items.

Those made to feel lower on the social totem pole said that a higher percentage should be spent on charity.

So what is it about being less well-off that causes people to be more generous?

In other experiments, the researchers found evidence that lower-class participants’ greater tendency to perform kind, helpful—or “pro-social”—behavior could be explained by their greater concern for egalitarian values and the well-being of other people, and their stronger feelings of compassion for others.

However, the researchers also found that when they induced feelings of compassion in upper class participants, those people showed just as much pro-social behavior as lower-class participants. This suggests to the researchers that the rich aren’t as generous as the poor because they don’t typically feel as much compassion for others.

Piff and his colleagues argue that the poor may feel more compassion because they are more connected to those around them, psychologically and socially. They are more dependent on other people to get by, for instance, and previous research has found that, perhaps as a result of that dependency, they display more empathy and are more attuned to other people’s body language than the rich. On the flip side, as people attain higher status, their ability to take others’ perspectives is diminished.

Piff and his colleagues’ findings have profound implications at a time when the richest one percent of Americans now owns more than the combined wealth of the bottom 90 percent.

“Our data suggest that an ironic and self-perpetuating dynamic may in part explain this trend,” write the researchers in their study, soon to be published in the Journal of Personality and Social Psychology. “Whereas lower-class individuals may give more of their resources away, upper-class individuals may tend to preserve and hold onto their wealth. This differential pattern of giving versus saving among upper- and lower-class people could serve to exacerbate economic inequality in society.”