The advancement of Henry Ford's Model T automobile was changing all aspects of society as it became more affordable. Teenagers began using them to spend more time together and to go out of town or to places that would soon become social gathering places. Historians say this is the origin of transitions that “broke tradition” (“The Invention of the Adolescent”). During the survey, 47.6% of girls and 45.4% of boys cited the time they came home or the number of times they went out as the main source of disagreement with their families (“Modern Youth in the 1920s: Collected Comments”). This was because cars had made old-fashioned courtship obsolete and dating had become common practice. Additionally, busing made it possible to expand school zones, turning one-room schools into larger buildings, giving teenagers the chance to meet more people in their age group, instigating peer pressure, and discussing unpopular topics.