Results showed teens tend to choose same-race friends, even as the opportunity to choose friends from different races increases.
However, school practices regarding academic tracking, extracurricular activities and student mixing by grade can help promote friendships among students of different races, the research found.
The study suggests that schools interested in promoting substantive racial integration should encourage activities that help students of different races work together, said James Moody, author of the study and assistant professor of sociology at Ohio State University.
"True integration takes more than just having people of different races in a school," Moody said. "What really matters isn't the mix of students as much as what the schools do with the mix of students."
The study appears in the current issue of the American Journal of Sociology.
Moody said that schools should try to ensure that extracurricular activities include students from all races; that students aren't "tracked" into separate academic programs based on race; and that grade levels are segregated so students are more likely to mix with students from their own grade.
This study used National Institutes of Health data from the National Longitudinal Study of Adolescent Health, a survey of adolescents in grades 7 to 12. The study included a representative sample of 130 public and private high schools and middle schools from across the country. In total, 90,118 students completed surveys. Each participant was asked to identify up to 10 friends (five male and five female) from their school and the corresponding middle or high school.
Moody then analyzed the racial composition of these friendship groups and matched the results with various school characteristics and practices.
On average, the odds of a teen naming someone of the same race as a friend were about twice the odds of naming a friend from a different race, after accounting for the number of students of different races in a school and, therefore, the opportunities for cross-race friendship.
The results showed that the likelihood of segregated friendships increased as a school's racial diversity moved from moderately low to moderately high, but declined at the highest levels of diversity.
"When you get larger minority populations, they reach a size where you can have a viable single-race community," Moody said. "At that point, students find enough friends within their own race and don't tend to make cross-racial friendships."
However, once racial diversity becomes very high, students become more likely to have cross-racial friendships, the study showed. This most often happens when there are more than two racial groups in the school, Moody said.
"When there are only two races in the school, there is a greater likelihood for 'us vs. them' social dynamics," Moody said. More cross-race friendships seem to occur when you have diverse populations of whites, blacks, Asians and Hispanics in a school.
But Moody said schools' practices play a large role in whether cross-racial friendships will occur. The strongest factor affecting friendship integration was extracurricular mixing. Schools that succeed in mixing students by race in extracurricular activities had the highest levels of friendship integration.
This effect extends beyond those that participated in the activities; in schools with integrated extracurricular activities, even students who didn't participate were more likely to develop cross-racial friendships, according to the study.
Friendship integration was also more common in schools that segregated students by grade - in other words, freshmen spend most of their time with other freshmen, for example. That means students have fewer peers of the same race to choose from when developing friendships.
"So if a freshman wants to find other skateboarders, he has to skateboard with both black and white kids, because he doesn't meet any sophomore skateboarders. Unlike racial segregation, which can reinforce stereotypes that last a lifetime, grade segregation is fairly innocuous since it disappears after graduation," Moody explained.
Schools may be able to achieve grade segregation by arranging schedules so students share lunch times, study hall and other free periods only with students of their grade level, Moody said.
Moody also found fewer cross-race friendships in schools that had strong academic tracking. These might be schools where most of the blacks are in non-academic tracks such as shop, and most of the whites are in the college-preparatory track.
Overall, the results point to the key role school practices play in truly integrating schools.
"Simply exposing students of different races to each other may not promote integration. If you walk in the lunchroom and all the black kids are on one side and all the white kids are on the other, they are living in separate worlds. There have to be specific practices that help overcome the tendency for people to self-segregate."
Funding for the study came from the National Institute of Child Health and Human Development, other offices of the National Institutes of Health, and the Department of Health and Human Services.
Written by Jeff Grabmeier, (614) 292-8457; Grabmeier.email@example.com