Rather than defining identity in terms of individuality, we defined it in terms of relationships with others. People know who they are on the basis of their relationships with others in their culture, community, religion, and family. We developed a measure of identity with four subscales and gave it to six adolescent groups in Experiment 1. We revised it and gave it to another six groups, five adolescent and one adult, in Experiment 2. We further revised it and gave it to three groups, two adolescent and one adult, in Experiment 3. Identity scores increased with age and four factors emerged: family, religion, community, and culture. Identity can be defined and reliably measured in terms of relationships.

The rate of safety belt use for drivers and front-seat passengers was examined by direct behavioral observation during the warning and enforcement phases of a mandatory use law in North Carolina. A substantial increase was noted in belt use for both groups once enforcement was initiated but has slowly eroded over time. Both drivers and passengers exhibited much higher rates of use when the other front seat occupant was also using a safety belt, suggesting the importance of behavior modeling.