On May 1, Facebook announced that its users would be able to make their decision to register as an organ donor public for their friends or for the world. By the end of the day, 100,000 users had reported they were organ donors, each with a news item on their “timeline.”

Many of the users who proudly proclaimed their organ donor status were new donors. In the first six days of the campaign—in which Facebook partnered with Donate Life America—94,000 people clicked onto the Donate Life America Facebook page for directions to join their states’ organ donor registries. During the same time, 33,400 people joined state registries, according to David Fleming, president and CEO of Donate Life America.

This influx of new donors generated a spike in the number of registrations. In California, where an average of 70 people join the registry daily, 3,900 new donors registered on the day of the Facebook announcement, according to USA Today.

So is Facebook solely responsible for this jump? Research within economics and psychology suggests that social broadcasting can be exceptionally powerful. Individuals respond to information about the actions of others when deciding whether to behave pro-socially (i.e., in ways that benefit others). In a study on charitable giving, Bruno Frey and Stephan Meier found that students are more likely to make a donation to charitable funds at the University of Zurich when they are told that 64 percent of students had donated historically than when they were told that only 46 percent of other students had done so.

In another study, Jen Shang and Rachel Croson found that individuals who call into a pubic radio campaign give more money when they are told about a recent donor who gave a large amount rather than a small amount or when a recent donor was not mentioned.

In the domain of environmental protection, Noah Goldstein, Robert Cialdini and Vladas Griskevicius found that guests at a hotel are more likely to hang and reuse their towel when they are told that 75 percent of hotel guests hang and reuse their towels than when they are provided with a generic environmental appeal.

Without a deep dive into Facebook’s data, we can only speculate how many of the thousands of new registrations came from heightened organ donor awareness generated by Facebook. If the social forces are as powerful in this domain as the research has shown them to be in others, then Facebook could presumably generate even more donors by prioritizing (or even rebroadcasting) news items about organ donor registrations, making it more likely that users will see stories about their friends becoming donors.

More broadly, the ongoing research on the strength of these social forces and the mechanisms by which they influence behavior can make all kinds of appeals more effective. Harnessing these social forces is a promising direction for research and policy. It is even more promising if we can leverage social hotbeds like Facebook, where these forces run wild.