Generosity rose among 9-year-olds but fell among 6-year-olds after a 2008 earthquake, the study found.

Generosity rose among 9-year-olds but fell among 6-year-olds after a 2008 earthquake, the study found. (E+, Getty Images)

Generosity increased dramatically, albeit temporarily, among a group of 9-year-olds but declined among 6-year-olds soon after a major 2008 earthquake in China, according to an international team of researchers that included a University of Chicago scientist.

Researchers were already working with the children in a different experiment about a month before the magnitude-8 earthquake in Sichuan province in May 2008 and tested them again one month after the natural disaster and then again three years afterward.

The U.S.-Canadian-Chinese study, which has been accepted for publication in Psychological Science, measured the youngsters' altruism with an oft-used, child-friendly method called the dictator game.

In the game, researchers showed children 100 stickers and asked them to select the 10 they preferred. They were then asked if they would give some of the stickers to an anonymous classmate not participating in the study. If they were interested in sharing, they would place one or more stickers in an envelope and seal it.

The researchers did not watch the children put the stickers in the envelopes. But later, unbeknownst to the children, they unsealed the envelopes and counted the number of stickers each child had donated.

They found that, soon after the earthquake, 9-year-olds' generosity almost tripled and the 6-year-olds' willingness to share with their classmates decreased by a third. The children's altruism returned to normal levels after three years.

"I was really interested to see what would change. It shows altruism is there for sure, but when you are young, your altruism is fragile," said Jean Decety, a U. of C. professor of psychology and psychiatry who helped conduct the study. Decety also is co-director of the brain research imaging center at the university's medical complex. "It is an acute (temporary) effect, which is good. It shows we are resilient, and after years or months, come back to normal levels of altruism."

Decety worked with Yiyuan Li, from Southwest University and Mianyang Normal University, both in China; Hong Li, from Liaoning Normal University in China; and Kang Lee, from the University of Toronto.

The next steps in the research are to examine the neurobiological foundation of morality in babies and young children. The research will use behavioral tasks to assess basic elements of morality, such as sensitivity to fairness, sharing and social evaluations, Decety said.

Liane Young, assistant professor of psychology at Boston College, and director of the school's Morality Lab, called the study "a fascinating study of how natural disasters can powerfully affect children's moral actions." Young was not involved in the study.

"Our intuition may be that when resources are lacking, people will become more selfish and more self-centered. This study suggests that, on the contrary, a natural disaster such as an earthquake can trigger children's empathic tendencies; empathetic children appear to become less self-centered and more other-oriented in the wake of a disaster," Young said.