Acceleration of the development of children and adolescents

Acceleration began to emerge at the end of the 19th century — first among the offspring of the most well-to-do segments of the urban population, and in the second half of our century it spread to all strata and almost all developed countries. Acceleration of the development of children and adolescents is part of a wider complex of phenomena, called the secular trend (literally, the trends of the century).
This includes the increase in general of all indicators of the physical development of the population (height, body weight, etc.), and earlier puberty, and a later onset of menopause in women, and an increase in life expectancy, and many others. There are negative traits in the secular trend - general “aging” of the population, the prevalence of small families and childless families, etc. To them, from our point of view, you can add the actualization of the problem of infantilism - against the background of accelerated peer mass, infantile adolescents find themselves in a particularly difficult situation .
Acceleration is most prominent in adolescence. In the 60s-70s, Moscow teenagers at 15 were taller than their peers in 1927: boys were an average of 10 cm, and girls were 6 cm. One of the signs of the completion of physical maturation is, as is known, the cessation of growth. In accelerated young men, growth began to end by 17–19 years instead of 23–25 years in the past, and among girls by 16–17 years instead of 21–23 years before. Compared with the cohort of adolescents in the 30s-40s, all indicators of skeletal ossification “looked younger” by 1-3 years. Puberty also accelerated - girls began to begin their monthly periods a year and a half earlier.
Acceleration is not only about physical development. Modern social life makes higher demands on the nervous system of adolescents than half a century ago. The flow of information has become incomparably more abundant, the impressions are more varied and richer, the pace of life is more accelerated, and education is more complex. Physical acceleration was undoubtedly combined with a certain acceleration of mental development, especially in terms of intelligence and abilities. New programs in primary schools, successfully introduced in the 1960s, not only confirmed this, but may have given a favorable incentive to accelerate intellectual development.