How Our Need To Reciprocate Could Be The Key To Getting Healthy

The researchers ran a rigorous, randomized field experiment with 1,700 pairs of participants in an online Twitter-like platform for runners. They devised a test to see what motivated inactive runners to hit the ground again to log 18 miles in two weeks. They were astonished by the results.

In the experiment, one group was challenged to run the 18 miles to earn a raffle ticket to win prizes from the online platform if they completed it. In another group, individuals received a raffle ticket from a friend on the platform for the chance to win prizes, then were given the opportunity to reciprocate and earn the same chance for that friend by running the 18 miles. The group that had to run to earn prizes to pay back their friends was 32% more likely to actually complete the challenge than the participants who ran to earn prizes for themselves.

"Most academic studies examine reciprocity in a lab setting with very short time-spans, like within a few hours. Ours is in a real-life setting, it goes beyond hours to two weeks, and it's asking people to run 18 miles, which is really non-trivial. And it works – marvelously well," says Gao. "We are very impressed with the power of reciprocity."

The results also reveal that the magnitude of the effect hinges on how well-acquainted the givers and receivers are. The researchers found the effect was strongest when the people knew each other moderately well, but not too well.

"We find that reciprocity is strongest with friends who are somewhere in the middle," Agarwal says. With people who are nearly strangers, you're not concerned with maintaining a relationship – you'll likely never talk to them again anyway, so why reciprocate? And with your closest friends, you know they won't hold it against you if you don't repay them.

A big part of the research was about marrying incentives to drive behavior with what's now possible with digital technologies – social media platforms, ubiquitous mobile devices and wearable technology, like Apple watches and Fitbits that constantly monitor behaviors and health. Because of this, reciprocity is much easier to implement as a motivator than ever before, say the researchers.

Organizations can use these findings to roll out reciprocity-based programs that are much more cost-effective that the types of incentive programs they currently offer, the researchers say, because unhealthy behavior isn't just bad for individuals – it strains health care systems and costs organizations and governments lots of money. Incentive programs that include a reciprocity element can make dollars go further and be more effective.

"It's not only just about giving people money or financial incentives; it's really about how you use that money smartly to get the best return on investment," Gao says.

Companies could use their organization-wide intranet to create reciprocity-based health challenges, or even offer small-scale challenges within a single department.

"But the power of this would really come from the large-scale social media platforms," Agarwal says. "Think about Facebook launching these healthy-behavior-generating programs – I think that would be a very exciting opportunity and it would have a huge impact on public health."

Agarwal and Gao say the benefits of paying back a friend's gift likely go beyond physical health to positively affect mental health, too. "We believe that it will make everyone happier," says Gao. "It could have very powerful effects on mental health."

This research fits into the larger mission at the Center for Health Information and Decisions Systems (CHIDS) to nudge people toward behavior change that will drive them to more healthy lifestyles. CHIDS is all about leveraging technology to figure it out, says Gao, "So we can nudge people at the right time, in the right scenario, using the right message."

Read: "Reciprocity or Self-Interest? Leveraging Digital Social Connections for Healthy Behavior," in MIS Quarterly.