At what age does the "young adult" developmental stage begin?

The "young adult" developmental stage is typically recognized as beginning around the age of 19. This stage is characterized by significant physical, emotional, and social maturation as individuals transition from adolescence into adulthood. During this time, young adults often explore their identities, pursue education and career opportunities, form intimate relationships, and begin to take on greater responsibilities in various aspects of their lives.

This classification aligns with developmental theories, which suggest that the young adult phase encompasses ages roughly from 19 to the mid-20s, coinciding with various milestones such as completing higher education, starting careers, and establishing independent living situations. Additionally, 19 is often seen as a pivotal age in many cultures where one transitions from the teenage years into adulthood, leading to more autonomy in decision-making and personal relationships.

The other ages listed do not accurately represent the onset of young adulthood within commonly accepted frameworks of human development. For instance, birth and early adolescence occur well before the young adult stage, whereas the age of 41 typically falls within the middle adulthood period.