Young Laughter Friendship across ethnic lines is common at every age, when schools, workplaces, and neighborhoods are not segregated. However, past history has an impact: These two girls share so much that they spontaneously laugh together, unaware that this scene in a restaurant could not have happened 50 years ago. Many of the youngest cohorts have trouble understanding lynching, poll taxes, separate swimming pools, or even the historic March on Washington in 1963.