Lecture 12 - Fertility And Demographic Transitions Flashcards
What is the average replacement TFR?
Refers to the minimum number of children required to keep the population steady
Normally about 2.1 ( replaces your mum and your dad )
What is the replacement like in modern society?
In modern society we have sub-replacement by choice
What is a common myth associated with the birthing rates of the rich and poor?
It is a common myth that poor people have lots of children so they have someone to look after them when they are old
Rich people have fewer children because they have pensions and savings to look after them.
Why is this idea wrong?
The myth is wrong because resources flow down the generations, therefore more and more children mean higher levels of poverty
Under ancestral conditions was there a planned family size?
No, it was simply the consequence of frequent sexual activity. You would simply have sex regularly and therefore whenever you were fertile you would have a child.
No birth control
What was the age of menarche in hunter gatherer society? Why ?
The age of menarche was later in hunter gatherer society, because the diet was was not very fatty or energy full, so their body weights did not signal maturity to be pregnant.
Whereas in modern society we have very energy rich food and therefore children who are fatter signal that they have the body nutrition to carry a child and start their period
What was the average amount of children a hunter gatherer could have and what limited them?
6
Limited by their late menarche
Then you have 9 months gestation
Can’t breastfeed more than one childon a hunter gatherer diet
So that means children are spaced 3-4 years and they have a total of 20 years fertility before menopause.
There have been 6 major demographic changes since hunter gatherer society. List them the first 3 up to the industrial revolution
- Hunter gather TFR = 6. Population is stable and not growing, humans reproduce as often as they have sex and child mortality is high
- Agriculture - higher fertility & higher mortality. Shorter lifespans. Population is denser but they are born quicker and die quicker. More reproductive success in the rich
- Industrial revolution - reduced mortality rates especially in children and high fertility, leads to massive increase in population.
List the final 3 demographic transitions
1st demographic transition - reduced voluntary fertility. Starts with the wealthiest and most intelligent and spreads downwards. Slowing of population growth, but still growing
2nd demographic transition - further reduction in fertility and population goes into subfertility, due to the legalisation of abortion and contraception in the 60s. There is population ageing and decline in the native western population
3rd demographic transition - subfertile population of the developed countries are being replaced by the highly fertile populations from underdeveloped countries (who are in the 1st transition stage). World population is still growing but growth is declining.
What are three reasons for the 2nd transition?
Secularisation ( loss of religion ) and therefore more contraception
Mass education extending further into the fertile years leads to later pregnancy or no pregnancy
Mass economic role of women
What explains the pattern in demographic transitions? (3)
The mismatch between ancient instincts and adaptations within new environments
Bruce’s idea of genetic damage and mutation accumulation
Why do we have such a weak desire to reproduce?
What are the four implications of these demographic changes?
1) knowledge may change behaviour, subfertility is a choice
2) the only antidote to subfertility in modern countries are some religions with traditional ethics and patriarchal views like Mormons, Amish, zionists and Muslims
3) some technology solutions, test tube babies - transhumanism
4) present trends continue
What is the TFR?
It’s a statistic, total fertility rate
The average number of children born to an average woman over an average life span