However, the analysis also found that in schools with the highest levels of diversity, the likelihood of choosing friends from one's own racial group decreases, and students are more likely to form friendships with people in other groups.
"This study shows that in many schools, children with similar backgrounds are likely to form friendships," said Duane Alexander, M.D., Director of the NICHD. "The study also points the way for schools to take the steps that make it easier for children from different groups to get to know each other."
Even in schools with students from many racial backgrounds, "kids are often graduating from essentially segregated schools, with little meaningful exposure to other races because they never form relationships with students of another race," said the study's author, James Moody, Ph.D., Assistant Professor, Ohio State University. "They are viewing other racial groups at a social distance, which can bolster stereotypes."
Dr. Moody analyzed information from a national sample of middle and high school students based on data from the National Longitudinal Study of Adolescent Health, a survey supported by NICHD, other NIH Institutes, NIH offices, and the Department of Health and Human Services. The survey measured the effects of family, peer group, school and other factors on behaviors that promote good health, as well as on health risks.
The researchers noted that, on average, the odds of a teen naming someone of the same race as a friend were about two times the odds of naming a friend from a different racial group, after they statistically accounted for the number of students of different races in a school and the opportunities for cross-race friendships in a school.
Dr. Moody reported that the likelihood of segregated friendships increases as a school's racial diversity moves from moderately low to moderately high, but it declines at the highest levels of diversity. According to Dr. Moody, this may be because schools with the most diverse populations have more than two racial groups.
"When there are only two races in a school, an 'us vs. them' social dynamic is likely to develop," said Dr. Moody. "With more groups within a school, however, multiple dynamics may lessen racial segregation. For example, some racial groups may serve as 'bridges' between two other groups. In addition, when there are multiple racial groups, every group is a small minority relative to the rest of the school.
"While friendship segregation is a common outcome in racially heterogeneous schools, it need not be," Dr. Moody wrote in the paper. "The ways that schools organize student mixing has a strong effect on interracial friendship patterns."
Specifically, Dr. Moody found that interracial friendships are more common in schools with integrated extracurricular activities. Cross-race friendships occur both within the extracurricular activities and throughout the school as a whole, suggesting that integrated extracurricular activities promote a school climate favorable to cross-race friendship. These activities include clubs, such as newspaper or drama, as well as sports teams. Dr. Moody also found that students' interracial contact increases when contact between students in different grades is limited.