Your friends may be determined by whom you see, where you live, and what you do more so than race, Harvard and UCLA researchers say.

Using Facebook friend activity data, Harvard Sociology teaching fellow Kevin Lewis and UCLA Sociology Professor Andreas Wimmer studied how factors such as ethnicity, race, geographic proximity, and common interests affect the formation of friendships.

The findings, published Monday in the American Journal of Sociology, reveal that race plays a much more minor role in explaining the basis of friendships than previously thought.

“Just because people are friends and of the same race doesn’t mean that that’s why they are friends,” Lewis said.

The pair compiled a database of Facebook activity from about 740 college freshmen. By tracking friends “tagged” in Facebook photos and comparing listed interests and extracurricular activities, the researchers were able to find associations among students.

In deciding how to measure friendship, Lewis said that looking at friend requests was not a sufficient method.

“We weren’t satisfied with just Facebook friendships because there was little meaning,” he said.

By tracking which friends were tagged in photo albums, they were able to more accurately identify friendships “as they occur outside of online interaction,” Wimmer said.

“Picture-posting is a stronger measurement of friendship. If you took a picture of someone, took the time to tag the picture, you probably have a stronger relationship with them because it is inferred that you were spending time with one another,” Lewis said.

The researchers also analyzed personal information, listed interests, and similar social characteristics displayed on Facebook profile pages.

The study also revealed that roommates, former classmates, and people of similar ethnic backgrounds were most likely to bond.

Roommates were seven times more likely to form friendships. Asian students were 31 percent more likely to form bonds with similar ethnic identities; Caucasians were 25 percent more likely; and African-Americans and Latinos twice as likely.

“There’s a misconception that people go out and seek out people who are like them,” Wimmer said. “But it’s not true—it’s the social and physical constraints.”

Lewis noted two unanticipated correlations in the data: students from Illinois and Dave Matthews Band fans in particular tended to befriend one another.

Wimmer added that the study’s findings are not limited to college students.