Forget, for a moment, all the usual benefits of public transportation, like cutting greenhouse gases and reducing traffic. There is a new reason to ride the commuter rails: They provide researchers an excellent laboratory for studying human behavior.
The most recent such study, conducted on several commuter rail platforms in the Boston area, finds that mixing with people of different ethnic backgrounds can influence social acceptance, at first for the worse, but then for the better.
“These things like public transit and the way we build our cities very much affect how we interact with people and how we get along as groups,” said Ryan D. Enos, assistant professor of government at Harvard and author of the study, released Monday. “When we invest in infrastructure, we bring intergroup harmony by encouraging people to interact.”
Enos’s study focused on the reactions of routine commuter rail riders after they began seeing Mexican immigrants, placed by researchers on nine train platforms between Worcester and Franklin and South Station. After just three days, riders showed increasingly anti-
But, after 10 days, their negative feelings began to subside, a sign, Enos said, that routine exposure to unfamiliar people on public transportation, though initially jarring, can shift attitudes for the positive in the long run.
Enos, who has conducted studies on segregation and the role that race plays in politics, said the commuter rail experiment was born from a need to find a way to test for prejudice in a real-world setting. Changes in attitude about race or culture are difficult to test in a laboratory, he said, because people are rarely willing or able to report their own subconscious biases accurately.
In the past, studies about the effects of interactions between different ethnic groups have been performed in other settings, with cross-cultural pairings of college roommates, for example. But those studies were difficult to orchestrate and failed to represent a wide cross-section of people.
“We’re probably not going to start randomly buying houses in a neighborhood and move people in,” Enos said. “We wanted to use the infrastructure of a city to simulate changes that people would experience if they were exposed to different types of people in their day-to-day life. We thought, ‘Where in the world do we see that kind of routinized behavior?’ ”
The answer: on public transportation, especially commuter rail systems, where people grow accustomed to taking the same train every day and are quick to notice new faces.
Public transportation, Enos said, may be the best laboratory for social scientists studying intergroup relations.
“It’s almost like a great experiment every time somebody steps on a bus,” Enos said. “If we can somehow capture their behavior when they step into this natural experiment, it can teach us a lot about humans.”
Enos and his staff took to Craigslist to enlist pairs of Mexican immigrants, mostly men in their 20s, to wait every day on platforms on the Franklin and Worcester/Framingham line. The immigrants were instructed to stand at the platform, but were not told what to say to one another or that they needed to speak at all.
“Because we are chatting in Spanish, they look at us,” wrote one of the Spanish-speaking riders in a report to Enos. “I don’t think it is common to hear people speaking in Spanish on this route.”
Routine riders were asked to fill out surveys before and after the new faces appeared on their usual weekday morning commute. Enticed with $5 gift cards, the respondents, 83 percent of whom identified themselves as white, answered myriad questions, including three pertaining to immigration.
At first, commuters were not fans of the new faces on their commuter rail platform, at least according to their reported views on immigration. Compared with initial survey responses, the routine riders who had noticed the new Spanish-speaking riders for three days were less enthusiastic about increasing the number of immigrants in the United States, less willing to allow undocumented immigrants to stay in the country, and more likely to believe that English should be declared the country’s official language.
“People’s attitudes moved sharply in this exclusionary direction,” Enos said. “I was surprised that the effects were strong.”
But, after a little more than a week, those views softened, though respondents were still warier of immigrants than when the experiment started.
In his paper, Enos argued that the study suggests what may come regarding national attitudes on immigration.
“Regions predicted to become more diverse should expect initial conflict,” Enos wrote. “However, these results also suggest that more prolonged contact or interpersonal interaction can diminish initial exclusionary impulse.”
Enos also argues the study makes the case that public transportation can be a force for good by eventually diminishing prejudices between disparate ethnic groups.
But Sam R. Sommers, associate professor of psychology at Tufts University, said Enos’s study paints a too-rosy picture of the potential for public transportation. A train platform or the seats on a bus rarely offer an opportunity for meaningful, substantive conversation or interactions, said Sommers. And, he pointed out, respondents in Enos’s study were still warier of immigrants after the experiment began, even if their reactions were more muted after two weeks.
But, Sommers said, Enos’s research confirms studies of cross-cultural interactions in workplaces, schools, or the military: Initially, people are uncomfortable, and tensions are high. But after a while, people begin to develop more positive feelings toward the people who at first made them uncomfortable.
“The initial effects of diversity can be negative and tough,” Sommers said. “But, with time, negative effects on cohesion and morale begin to diminish, and diversity starts to become an asset.”
A more optimistic note came from the Spanish-speaking workers themselves, who said they felt more comfortable by the end of their two-week stint on the commuter rail.
“People have started to recognize and smile to us,” wrote one.
Another was approached by one of the commuter rail regulars.
“The longer you see the same person every day,” the regular rider told the new arrival in the train station, “the more confident you feel to greet and say hi to them.”
Martine Powers can be reached at firstname.lastname@example.org. Follow her on Twitter @martinepowers.