Coming of age
In the United States, teenagers are allowed to drive at 16 in all states except New Jersey, which requires drivers to be 17 and older, and sometimes receive the responsibility of owning their own car. Teenagers may drive at age 15 in Idaho and Montana. At 16, teenagers are also old enough to donate blood and work in most establishments. At 18 one is legally considered an adult and can vote and join the military. The legal age for purchasing and consuming alcohol and recreational marijuana, the latter of which is only legal in the District of Columbia, Colorado, Oregon, Washington, California, Hawaii, Massachusetts, Nevada, and Alaska, is 21. The legal age for purchasing and consuming tobacco products is 18 in most states; 19 in Alabama, Alaska and Utah; and 21 in California, New Jersey, Oregon, Hawaii and Maine. Multiple localities have also raised the minimum purchase age independent of state laws.
Adult
In most of the world, including most of the United States, India and China, the legal adult age is 18 (historically 21) for most purposes, with some notable exceptions:In contrast to biological perspectives of aging and adulthood, social scientists conceptualize adulthood as socially constructed. While aging is an established biological process, the attainment of adulthood is social in its criteria. In contrast to other perspectives that conceptualize aging and the attainment of adulthood as a largely universal development, regardless of context, nation, generation, gender, race, or social class, social scientists regard these aspects as paramount in cultural definitions of adulthood.