text: History In the United States during the early 1960s, the average age that young adults were marrying was 20 for women and 23 for men, which means young adulthood consisted of parenthood and continuing higher education. Young women concentrated on becoming full-time mothers, whereas men focused on their careers while parenthood took a backseat. In the 1970s, the average age for childbirth began increasing; by 2010, it rose to 26 years for women and 28 for men. As of 2021, the median age for marriage (not including re-marriage) was 28 for women and 30 for men. In the past, marriage and child-rearing have been considered the pivotal hallmarks of being an adult. As such, average ages of marriage and child-bearing can indicate when individuals are reaching "adulthood". As the average ages for marriage and child-bearing have increased, they indicate the time in which emerging adulthood began developing as an additional stage in adult development.
  Jeffrey Arnett pointed out four revolutions that changed everything people knew in the 1960s and 70s and contributed to the existence of the emerging adulthood stages of life—the technology revolution, the sexual revolution, the women's movement, and the youth movement. Each of these movements led to impacts on the actions and development of people in separate ways. However, the culmination of all of these events led to the characteristics of emerging adulthood as a stage listed above.