section_path: Demographics
section_name: Demographics
paragraph_text: Demographics
  
  Friends tend to be similar to one another in terms of age, gender, behavior, substance abuse, personal disposition, and academic performance. In ethnically diverse countries, children and adolescents tend to form friendships with others of the same race or ethnicity, beginning in preschool, and peaking in middle or late childhood. As a result of social separation and confinement of the sexes, friendships between men and women have little presence in recorded history, having only become a widely accepted practice in the 20th century.