By Roberta Kwok
We tend to become friends with those who are like us, for example, people of the same ethnic or religious background or a similar personality. A new study co-authored by Balázs Kovács of Yale SOM suggests that invisible and visible clues may be part of this process. Specifically, the study examined whether subtle similarities in the way people write or speak, such as the types of words they use, make a difference in determining whether a relationship is formed.
Kovács and Adam Kleinbaum of the Tuck School of Business at Dartmouth College studied online connections between Yelp users and found that people seem to be attracted to others with similar language styles. A similar trend, although weaker, emerged in a study of in-person friendships at a university. And after two people became friends, their use of language tended to stay more similar over time.
“These are dimensions that you might not consider important,” Kovács explains. But “linguistic things matter”.
The results provide more evidence that people tend to congregate in echo chambers, Kovács says. If people get together with like-minded peers, and those friends become even more similar over time, society will fragment into polarized camps.
“What you would get are pockets of society that are very similar to each other,” he says. Linguistic style is probably not the most important factor in creating these links, but “maybe it’s part of it”.
Read the study: “Similarity of linguistic style and social networks”
Kovács and Kleinbaum began by examining online relationships. They hypothesized that language could play an important role in this framework. After all, people have far less information about their potential friends in a digital environment than in person, where they can assess other factors such as appearance, facial expression, and tone of voice.
Online, “you usually have no idea who these people are,” Kovács says. Instead, users primarily rate others based on what they write.
To investigate, the team analyzed 1.7 million Yelp reviews by nearly 160,000 users in seven North American metropolitan areas: Phoenix; Las Vegas; Pittsburgh; Urbana-Champaign, Illinois; Charlotte, North Carolina; Madison, Wisconsin; and Toronto.
The researchers used a language coding framework developed by another team to score each user in 18 categories. For example, they determined how often the person used first person singular pronouns such as “I”, “me” and “mine”; negations such as “not” and “never”; and comparison words such as “bigger” and “better”.
For each possible pair of people within each metropolitan area, the researchers calculated the similarity of their language styles. Next, the team checked to see if this pair had identified as a friend on Yelp.
They found that a one standard deviation increase in likeness was associated with a 26 to 76 percent higher likelihood of friendship, depending on the metropolitan area. The effect was strongest in Las Vegas and weakest in Urbana-Champaign, but “the main pattern is the same everywhere,” says Kovács. And a higher linguistic similarity in August 2016 was linked to a higher likelihood of forming a new connection between these users over the next five months, suggesting that the corresponding language styles had helped create friendships.
The more similar the language styles of the students, the more likely they were to remain friends. And the use of the language by friends tended to converge more over time than if they weren’t close.
The researchers were also curious whether people tended to adopt their friends’ language tics over time. They found that, on average, the language styles of Yelp users diverged slightly from each other from August 2016 to January 2017. But the gap widened less if two people were friends in 2016; in other words, their styles have remained more similar.
The online study left a few questions unanswered. The researchers didn’t have a lot of information about the users, so they couldn’t control for demographic factors and isolate the effect of language alone. It was also not clear if their results would hold up for in-person relationships.
For example, Kovács and Kleinbaum collected data from 247 students who had entered a university graduate program in the United States. They got two sets of writing samples: essays written before meeting their peers and review essays written two months after starting the program. The researchers also gathered demographic information and took the students for a personality test. One month and six months after starting the program, students responded to a survey asking them to list the classmates with whom they spent the most free time.
Again, the team coded the linguistic style of each student and the similarity of every possible pair of people. But this time, the researchers also checked for factors such as gender, race, nationality, and personality characteristics.
The general pattern was similar to that in the Yelp study, but with a less dramatic result: a similarity score one standard deviation higher was linked to a 5% higher likelihood of forming a friendship. The more similar their language styles, the more likely they were to remain friends at the end of the study. And when people were friends, their use of the language tended to converge more over time than if they weren’t close.
Why was the effect of language weaker for in-person relationships than online? Students probably relied on many other cues such as attractiveness and age to choose their friends. With Yelp reviews, “they only see the text,” Kovács says.
Kovács speculates that the effect of language may go beyond friendship formation. Perhaps people are also more likely to listen to other people who have similar language styles, which would affect the flow of ideas and opinions in society.
“It’s a more general phenomenon than friendship,” he says. “It’s about who influences whom. “