In his book, Why Civilisations Self-Destruct (Howard Allen, Cape Canaveral, 1977), Elmer Pendell rejected previous theories of why civilisations collapse and favoured heredity as a factor, saying "every civilisation normally has a built-in self-destruction mechanism, which insures that the less capable half of every generation become the parents of more than half of the succeeding generation". (p.117) This leads to a fall in problem-solving ability and ultimately a civilisation gets overwhelmed, and falls apart.
While I agree with this genetic dysgenic argument, there is more at work will stop there is a general process of social entropy or decay at work with a wide range of values. Affluence can speed up this process of social decay. Ibn Khaldun, the great Arab historian (see how multicultural I am!) In The Muqaddimah (i.e. The Introduction to his Kitabal’ibar or History of the Arabs) said:
"the goal of civilisation is sedentary culture and luxury. When civilisation reaches that goal, it turns toward corruption and starts being senile, as happens in the natural life of living things. Indeed, we may say that the qualities of character resulting from sedentary culture and luxury are identical with corruption. Man is man only in as much as he is able to procure for himself useful things and to repel harmful things, and in as much as his character is suited to making efforts in this effect. Those sedentary person cannot take care of his needs personally… He has no courage as a result of luxury and his upbringing under the impact of education and instruction. He has become dependent upon a protective force to defend him. He then usually becomes corrupt with regard to his religion, also… When the strength of a man and then his character and religion are corrupted, his humanity is corrupted and he becomes, in effect, transformed".
The West is already well into this process of decay. That's the United Nation’s special rapporteur on the human rights of migrants has said that attempts by Europe to "seal" its border will fail and that refugees should be able to settle where they want. Borders need to be open : "Europe Must Open Borders to Migrants, UN Official Says", February 12, 2015 at http://www.thestar.com/news/world/2015/02/12/europe-must-open-borders-to-migrants-un-official-says.html
This is the same United Nations that has told us in World Population Prospects : The 2012 Report that it needed to reuse its previous population projections : based on medium fertility assumptions the world's population would reach 10.9 billion by 2100. It will reach 8.1 billion by 2025 and 9.6 billion by 2050. That's just on the medium projection which assumes a decrease in fertility in countries where large families now occur. The high-variant projection assumes on average only an extra half a child per woman compared to the medium variant and that yields a world population of 10.9 billion by 2050 and 16.6 billion in 2100. There is another projection which is a business-as-usual, "constant fertility assumption" and that gives a world population of 28.64 6 billion! The changes in projections were necessitated by higher-than-expected birthrates in sub-Saharan Africa.
Niger has a population of 18 million now and is expected to reach 204 million in 2100; Tanzania, 49 million now, 276 million in 2100 and in high growth assumptions Nigeria's population in 2100 may reach 1.3 billion. However as John Derbyshire points out in his article "Four Billion Africans", September 25, 2014, at http://takimag.com/article/four_billion_africans_john_derbyshire/print#axzz3TIF5Dgj3, a study from the University of Washington, Seattle, predicts that by 2100 the African population will reach four, repeat, four billion. Fertility in sub-Saharan Africa has not been falling.
Derbyshire goes on to mistakenly think of this issue in terms of population density, noting that "Quadrupling the population of sub-Saharan Africa would… just put the place in the same league as the People's Republic of China, density-wise. What's to worry about?" The issue is not one of population density - the entire population of the world today could all faith in Tasmania. The question is carrying capacity, food and water for all of those people. 4 billion people are simply not sustainable in Africa.
What will happen, before any sort of Malthusian population crash is that the West's open borders attitude, forced by UN globalists will lead to a Camp of the Saints style flood of "refugees" and the ultimate swamping of Europe. A collapse of Europe would be interesting to capitalists, to say the least. Just think of the hundreds of Fukushima meltdowns likely to occur when civilisation breaks down. Imagine, if you can, money, glorious money - all radioactive.