In 1840, Puberty Started at 16. Today It's 11.9.
на канале: The Old Wiring
Everyone "knows" ancient humans became parents at 12 because they died by 30. Both halves are wrong — and the truth is stranger than the myth.
Our ancestors matured LATER than we do. Hunter-gatherer girls reached menarche around 16 and had their first child at 19. The number 12 comes from Roman law, not human biology.
Meanwhile, a 2024 Harvard study of 71,341 American women found the average age of a girl's first period has dropped from 12.5 to 11.9 in two generations. The earliest puberty in the history of our species isn't ancient. It's happening right now.
This video covers what actually happened, why it's accelerating, and what it means that our bodies are maturing earlier than ever while our lives start later than ever.
CHAPTERS
0:00 The Juliet problem
0:35 Myth 1: "They all died at 30"
1:40 Myth 2: When our ancestors actually matured
3:00 Where the number 12 really came from
4:20 The reversal: 16.5 → 11.9
5:40 Five reasons this is happening
6:40 Biology vs. culture
SOURCES
Wang Z, et al. "Menarche and Time to Cycle Regularity Among Individuals Born Between 1950 and 2005 in the US." JAMA Network Open, 2024;7(5):e2412854
Houghton LC. Invited commentary, JAMA Network Open, 2024
Gurven M & Kaplan H. "Longevity Among Hunter-Gatherers: A Cross-Cultural Examination." Population and Development Review, 2007
Howell N. Demography of the Dobe !Kung, 2nd ed.
Hill K & Hurtado AM. Ache Life History, 1996
Wrigley EA & Schofield RS. The Population History of England 1541–1871
Hajnal J. "European Marriage Patterns in Perspective," 1965
Frisch RE & Revelle R. Science, 1970 (body fat and menarche)
Belsky J, Steinberg L & Draper P. Child Development, 1991
CDC / National Center for Health Statistics — US teen birth rates, 1991–2023
Historical context only. Nothing in this video endorses early marriage or early childbearing.
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#anthropology #humanevolution #history #science