And I'm Robert Siegel. Most of us like to think of ourselves as generous people. We volunteer, donate our time and open our wallets for charity, but perhaps we aren't as big-hearted as we think. Consider how much you give and compare it to how much you earn. NPR's social science correspondent Shankar Vedantam reports on research that suggests a paradoxical connection between those numbers.
SHANKAR VEDANTAM, BYLINE: Dacher Keltner is a professor of psychology at the University of California at Berkeley. His own life gives him a window into a paradox he studies in his experiments.
DACHER KELTNER: I grew up, you know, I guess from age 10 to 17, what you would call a pretty poor neighborhood out in the country of California.
VEDANTAM: Keltner saw what he would later study in psychology reflected in the lives of the people he was living with.
KELTNER: I saw open doors and barbecues in the backyard and kids playing all night and also the tougher side of husbands out of work and drinking too much and, you know, the health issues that go with impoverished circumstances.
VEDANTAM: As Keltner moved to Berkeley and carved out a busy professional life, his material concerns went away but something else happened. Those open doors and endless backyard parties? They started to disappear from his life, too. Keltner felt something inside him change, something about the way he relates to others.
KELTNER: I saw it personally. I feel it in myself, that somehow when I am thinking hard about making more money and, you know, rising in wealth and enjoying materialistic benefits, I do feel personally that I'm not as responsive to the needs of others.
VEDANTAM: Keltner will be the first to say his individual experience is only an anecdote, but Keltner, the scientist, would tell you that his data shows exactly the same thing. He's conducted dozens of experiments where he tests the generosity of individuals.
KELTNER: In just about every way you can study it, our lower-class individuals volunteer more, they give more of their resources, they're more generous.
VEDANTAM: This is the paradox. People who have more money ought to be able to give more away, but they don't. Now, you're probably thinking, hang on, that can't be true. Surely the rich give away more than the poor. Think about wealthy philanthropists who give away millions. The answer is, yes, in absolute terms, the rich do give more.
But Keltner thinks that's not the best way to measure generosity. A thousand dollars for a billionaire doesn't mean the same thing as $100 for somebody on the poverty line. Keltner cites a study conducted by Independent Sector, a network of nonprofit groups, that measured how much people give depending on how much they have.
KELTNER: The poor, say with family incomes below $30,000, $25,000, are giving about 4.2 percent of their wealth away, whereas the wealthy are giving away 2.7 percent.
VEDANTAM: Keltner's work on the paradox of generosity dovetails with new research from UCLA. Patricia Greenfield has looked at the words we use as a window into our attitudes toward one another. She recently analyzed the contents of more than a million books published in the United States between 1800 and 2000. She used a new Google tool called the Ngram Viewer that allows rapid analysis of large numbers of books.
Greenfield found there was a change over those two centuries as America grew wealthier. Some words became more common in books, some became less common.
PATRICIA GREENFIELD: The frequency of the word get went up, and the frequency of the word give went down.
VEDANTAM: There were changes in the words Americans used to describe themselves.
GREENFIELD: Words that would show an individualistic orientation became more frequent. So, examples of those words were individual, self, unique.
VEDANTAM: And the frequency of other words Americans used about themselves declined.
GREENFIELD: Words that would represent a more communal or more family orientation went down in frequency. Some examples of those words are give, obliged, belong.
VEDANTAM: Keltner and Greenfield, working independently, have both concluded that the poor tend to value social connections because social connections are integral to survival when you can't make your way on your own. Greenfield has followed generations of families in Mexico as they have become wealthier. She finds rural communities had strong social networks.
GREENFIELD: The wife may make the clothes for the whole family. The husband grows food and builds the shelter for the whole family. Therefore, giving, social obligation, belonging to a family are very important.
VEDANTAM: But slowly, as the communities became wealthier, people needed one another less, and so they made fewer connections. Autonomy and freedom took the place of responsibility and obligation. Neither Keltner nor Greenfield are offering a screed against wealth. As America has become richer, lots of good things have happened. Disease has declined. Education has improved. Women and minorities have gotten more equal treatment. But it came at a price.
KELTNER: As we rise in wealth, along with that rise in wealth comes ideas of individuality and self-expression and autonomy and freedom and loneliness.
VEDANTAM: Keltner says being wealthy does not inevitably mean isolation. But it probably does mean that the bonds of connection that came easily to us 200 years ago might now need to be carefully and deliberately cultivated. Shankar Vedantam, NPR News.