Due to different social, cultural, institutional, economic and political factors, different countries have subtle differences in the actual definition and understanding of the word "youth".
1985, the United Nations defined youth as 15 to 24 years old for the first time, without affecting other definitions of member States.
Extended data:
According to developmental psychology:
0- 1 year in lactation, 0-2 years in infancy, and 2-3 years in infancy.
Preschool 3-6, 7 years old. 6, 7- 1 1, 12 years old preschool.
Adolescence is 1 1,12-14, 15 years old. Youth 14, 15-30 years old.
Middle-aged people aged 30-50. After 50 years old.
In the world, the population is usually divided into unequal groups according to the age of 0~ 14, 15~64 and over 65 years old, which are called juvenile population, mature population and elderly population respectively.
The juvenile population coefficient, the mature population coefficient and the elderly population coefficient are calculated according to the total population, and the dependency coefficient is also calculated according to the mature population.
That is, dependency coefficient = (juvenile population+elderly population)/mature population 15~24 years old population is also called young population internationally.