Program Goals/Program Theory

Tribes is an intensive universal prevention strategy administered in elementary classrooms that is designed to reduce aggressive and violent behavior, reduce risk factors for the development of violent behavior later in life, and increase protective factors that enhance resiliency. This universal prevention strategy is based on the idea that intervention programs should build resiliency—not merely reduce risk factors—and should use the classroom environment as an agent of change.

Target Population

The target population for Tribes is elementary school children, specifically children in first through fourth grades.

Program Activities

Tribes is designed to be administered to an entire classroom through the entire academic year; it is integrated into the class curriculum. The key features of the program are to organize children into smaller learning groups called “tribes” and to develop a nurturing classroom climate that includes respect for others, teamwork, building relationships, and individual accountability.

Students and teachers agree to honor four critical agreements while in class:

  1. Listen attentively to one another.
  2. Show appreciation for one another.
  3. Show mutual respect.
  4. Agree that students have the right to not participate in Tribes-related activities if they choose not to.

In addition, children are taught to set goals, define expectations for themselves and their learning group (i.e., their tribe), and reflect on what was learned and how it was learned. There are 12 collaborative skills that students learn to work effectively together.

The Tribes program is not curriculum based; rather, it is constructed and implemented as a way to organize classrooms and teach children. Teachers receive 3 days of training, as well as onsite support, to learn how to restructure their classrooms and aid in the implementation of the Tribes program.

Additional Information: Negative Program Effects

An outcome evaluation (described in Evaluation Methodology and Outcomes) found that the program in general had no effects on children’s behavior when boys and girls were assessed as a group, but when girls were considered separately, the program had significant negative effects on girls’ behavior and academic performance.

Intervention ID: 
6 to 10
No Effects

Study 1

Hanson and colleagues (2011) used a cluster randomized trial to evaluate the impact of the Tribes program on first through fourth grade students in San Francisco and several other school districts throughout California. Randomization was done at the classroom level, as elementary school teachers are assigned to one class. Because of children’s rapid development, two separate studies were conducted with separate samples of first and second graders and third and fourth graders. The final sample consisted of 79 classrooms receiving the Tribes program and 74 classrooms serving as a control group. In total, 2,309 students were included in the study. Since treatment and control classrooms were contained in the same school, there was a concern that contamination (the Tribes program being used in control classrooms) could occur, but the researchers took every step possible to minimize this threat to the research design. Analyses indicated that the groups were equivalent at baseline.

The student sample was 22 percent Hispanic, 20 percent non-Hispanic white, 14 percent African American, 12 percent Chinese, 11 percent Filipino, and 21 percent “other” (which included those with missing race/ethnicity data). Sixty percent of students were eligible for free or reduced-price meals, and 38 percent were classified as English language learners. Attrition from the study was limited (13 of 166 randomly assigned teachers dropped out of the study).

Outcomes were measured upon completion of the program and 6 months afterward to detect any sustained program effects. Data was collected from multiple sources using a variety of instruments. A specially designed teacher survey was used to measure implementation and fidelity of the program. Items from the Achenbach Child Behavior Checklist and the Behavioral and Emotional Rating Scale (the BERS–2) were used to construct a checklist for parents and teachers to rate children’s prosocial and antisocial behavior. Additionally, trained researchers conducted direct observation of classroom environment and child behavior. Children were assessed through individual interviews that concentrated on moral judgment and on academic performance which was collected from archival records. Hierarchical linear modeling was used to conduct analyses.


Study 1

Although Hanson and colleagues (2011) detected some significant findings, the preponderance of evidence suggests that the Tribes program had no effect on reducing aggressive and antisocial behavior and made a detrimental impact on girls’ academic performance.

Aggressive/Rule Breaking Behavior

The results on the impact of the Tribes program are mixed when examining aggressive behavior. In the overall sample and according to both parent and teacher reports, there were no significant differences for aggressive or rule-breaking behavior, social problems, or attention problems—immediately postintervention and 6 months postintervention—between children receiving Tribes and control group youths.

Gender subanalysis suggests that the program had differential effects for boys and girls. There appear to have been more beneficial impacts for boys and more detrimental impacts for girls. However, reports on male behavior differed depending on the source for the first and second grade sample. According to teachers, boys receiving the Tribes program displayed more statistically significant increases in aggressive and rule-breaking behavior than boys in the control group. Yet, parent-reported rule-breaking behavior shows a statistically significant decrease for boys receiving the Tribes program, compared with boys in the control group. For the other sample, children in third and fourth grades, Tribes appears to be beneficial for males. According to teachers, boys receiving the Tribes program demonstrated significantly lower levels of aggressive and rule-breaking behavior, as well as fewer social and attention problems.

Girls participating in Tribes displayed higher scores in parent-reported measures of emotional and behavioral strengths, compared with girls in the control group. Additionally, for both boys and girls there is no evidence that any programmatic effects were sustained or emerged at the 6-month follow-up.

Academic Performance

The other significant impacts detected for girls receiving the Tribes program were detrimental. For girls in both samples, grades 1 through 4, those participating in the Tribes program exhibited statistically significant lower test scores in English and mathematics, compared with girls in the control group. The researchers are not sure why the Tribes program would be associated with marked declines in academic performance and only for girls.