Title: Hormones raging in immature minds
1Hormones raging in immature minds how the
mismatch between biology and society Contributes
to the problems of adolescence
Prof Peter Gluckman FRS Wellington Dec 2006
2- We have two histories
- an evolutionary history
- a developmental history
- Mismatch arises when those histories do not leave
us well matched to the world we live in - And our world has changed!
3- Humans evolved with features adapted to maximise
their fitness in the environments in which we
evolved. - Humans did not evolve for longevity or health
- Humans have had increasing impact on their
environment, particularly since the upper
neolithic, the development of agriculture,
settlement, technology etc etc
4(No Transcript)
5- Humans are now increasingly likely to be
mismatched to the environments they evolved to
live in - Social
- Communicative
- Nutritional
- Energetic
- We evolved to live in one world we live in
another - Obesity
- Myopia
- ? The post-menopausal phase of life
- The problems of old age
- PUBERTY
670
France
50
Longevity (years)
?
30
1750 1800 1850 1900 1950 2000
Neo
7Evolutionary novelty - adolescence
- Adolescence is a novel phase of life
- It does not really exist in hunter-gatherer
societies - It did not really exist in 18th century Europe
- It is a 20th century development
8 The mismatch of modern puberty
9Puberty is not a point in time
- Breast budding 7-12 years
- Pubic hair development starts soon after
- Growth spurt peaks 1 year after breast bud
- Menarche (first period) 2 years after breast bud
(9-14 years), breast development and growth spurt
almost over - Reproductive competence 1-2 years later (10-16
years) - Maximal pelvic size 4 years after menarche (13
18 years)
10- But the timing of puberty is changing
Redrawn from data in Ljung et al (1974) and de
Muinich Keizer Mul (2001)
11- The age of menarche fallen
- Is this evidence of pathology
- or a sign of health ?
12- Why has the age of menarche fallen ?
- Is this evidence of pathology or a sign of health
?
13OSLO, NORWAY
16 15 14 13
MEAN MENARCHEAL AGE (YEARS)
1800 1850 1900 1950
Ellison 1981, Hum Biol
14 Menarche in the European female
20y
AGE
10
Social Complexity, Nutritional overload
Indust revol Social improvement
Agriculture Settlement
20,000ya 2000ya 200ya present