Whether someone decides to return a favor to us might depend a lot on how exactly we helped them out in the first place, a recent study published in the journal Frontiers in Psychology suggests.

Researchers at the University of Southern California crafted a pair of door-holding experiments in order to examine whether the amount of effort behind a helpful gesture influences the recipient’s inclination to say thanks in return as well as their willingness to later pay forward a kind gesture to others, including the original helper. They found the more effort it took someone to hold a door open, the more likely they were to be thanked and later helped. Those who gave thanks, however, weren’t any more likely to also help out their compatriot, nor were they more likely to help out an unrelated third party immediately afterwards. Similarly, the level of effort put forth by the helper didn’t inspire test subjects to be more charitable towards anyone else besides the helper.

“In the current study, spontaneous social behavior was measured in a novel way that allows conclusions about how we perceive the things others do for us — and how we act in kind,” the authors wrote. “We see for the first time that verbal thanking and reciprocal helping are not inherently correlated.”

A Small Favor

In the first experiment, the researchers created a deceptively complex scenario. One condition saw the experimenter prop open the door for someone with as little visual effort as possible, by pretending to exit the building (USC’s Leavey Library) slightly ahead of the hapless subject while avoiding eye contact. Another involved someone entering the building the subject was able to leave, holding open the door and waiting for the person to exit through while flashing a great big smile and locking eyes. In either case, the subject would be confronted outside by a second experimenter (who didn’t know which condition the subject had just passed through) and asked to participate in a relatively long survey. A control condition would see the subject receive the survey pitch without any door assistance.

Out of the 120 test subjects who were appropriately approached (40 belonging to each condition), only 24 offered verbal thanks, but these thankers were more likely to belong to the high-effort condition. However, there were no significant differences between groups in their willingness to take the survey (39 of 120 did), nor in the length of time they chose to stick around and answer questions (participants were told they could leave whenever they wished). Thanking frequency also had no effect on the survey outcomes.

“It is possible that the absence of reciprocal helping was due to the fact that the person who held the door was not the same person asking for a favor,” the authors wrote, “It may be that upstream reciprocity requires a gesture large enough to motivate us to reward others outside of the original source of goodwill.”

With that in mind, the researchers conducted a more intimate experiment involving only the door holder and the subject. Just as before, there was a low and high effort group (194 successfully aided participants in total), but this time, the experimenter was also instructed to hold a filing box with another smaller box of 12 pens loosely stacked on top. Soon after they finished helping with the door and the subject walked through, they “accidentally” fumbled with the box, dropping their poor pens onto the floor. For added specificity, the drop happened at different distances after the subject walked through the door, requiring more or less effort on their part to circle back and help the experimenter. That resulted in 8 different conditions divided evenly among the two groups.

“Participants offered verbal thanks and reciprocated more frequently in the high-effort condition, and participants who offered verbal thanks did not help more often,” the authors concluded this time around. “Participants at every distance were more likely to help the door-holder if they were part of the high-effort condition than of the low-effort condition.” Overall, 50 percent thanked the experimenter, with an 85 percent proportion of thankers in the high-effort group compared to 31 percent in the low-effort group.

While this reciprocity effect has been seen in previous door-holding studies, there are possible caveats. “It is possible, for instance, that there are differences in how we treat someone entering a building as we exit compared to someone leaving a building with us and that we are broadly more likely to help those who are entering as we leave,” acknowledged the authors. Similarly, subjects could have seen the low-effort helpers as being rude for stepping in front of them (though the researchers tried to control for that), or they could have felt begrudgingly obligated to return the favor in the high-effort condition rather than having felt a sense of genuine gratitude. Even the fact that the first study involved a female helper and the second only males could have played a role in the results.

Despite these drawbacks, senior author Dr. Antonio Damasio, director of the Brain and Creativity Institute and the Dornsife Neuroimaging Institute at USC, believes there’s a lot to take away from his team’s findings. "This study shows that gratitude has consequences," he said in a statement released by the university. “It is not only the recipient of the act or gift who gains; it is also the doer or giver. When you are courteous to another person, or when you offer gifts, you are doing something that is good for you. Interestingly, it can be rewarding for yourself, and it can reduce stress. It can actually be good for your health."

Advocating for further research on the unintuitive connection between saying thanks and offering help, Damasio and his colleagues went on to conclude that they were “heartened by the many participants that, after receiving a trivial favor, spent considerable time to help a stranger.”

Source: Fox G, Araujo H, Metke M, et al. How Does the Effort Spent to Hold a Door Affect Verbal Thanks and Reciprocal Help? Frontiers in Psychology. 2015.