#39. The 1950 Ramp [population, evolutionary psychology, engineering, neuroscience]

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Red, theory; black, fact

A schematic of a simple rate-of-increase controller mechanism

Historical 

Since about 1950, the world population has been increasing along a remarkably steady ramp function with no slackening in the rate of increase yet apparent, although one cycle of oscillation in the slope occurred during the Sixties. Malthusian reasoning predicts an exponential increase, which this is not. Several lines of evidence point to the idea that humans have a subconscious population controller in their heads, and yet such a controller would have leveled out the increase by now. Until now, no theory has sufficed to explain the facts.

Human Population is Being Controlled for Endless Trouble

The natural population curve for humans in good times may be a saw-tooth waveform, with population ramps alternating with political convulsions that result in a large group being expelled permanently, resulting in the precipitous but limited drop in local population density that ends the saw-tooth cycle. This cycle accomplishes the ecological dispersal function. The population must ramp up for a time to sustainably create the numbers needed for the expulsions. The WHO population curve shows only a ramp because it is a worldwide figure and therefore population losses in expelling regions are balanced by population increases in welcoming regions. This also implies that human population has been increasing in a way unrestrained by food or resource availability or any other external constraint since 1950, to now.

Clearly, human population is being controlled; not to a constant absolute density, but to a constant rate of increase. Population density would go up along the much faster, steeper, and more disastrous exponential curve of Malthus if there were actually no controller.

Neuroscience Aspects

Researchers should look first for such a controller in the hypothalamus, already known to control other variables, such as temperature, by feedback principles.

"Nature does not reinvent the wheel" [quote from my old Professor], which I understand to mean that once a brain structure evolves to serve a particular computational function, it will be tapped for all future needs for such a calculation. This process may make it grow larger or develop sub-nuclei, but additional, independent nuclei for the same computation will never evolve.

Engineering Aspects 

The population controller may contain a conventional PID controller. To make it control rate of increase rather than absolute population density, you put a differentiator in the feedback pathway. If you are of the opinion that human population control is urgent, then you must knock out this differentiator and replace it with a simple feed-through connection. 

Back to Neuroscience 

Fortunately, one common way for evolution to implement differentiation in mammals is to begin with such a feed-through connection and supplement it with an inhibitory, slow, parallel feed-forward connection. If this is the case here, then you  inhibit the feed-forward pathway pharmacologically with sufficient specificity and the job is done. Subjectively, the effect of such a drug would be to take away people's ability to get used to higher population density in deciding how many children to have. An increased propensity to riot should not occur.

The political convulsions that produce dispersal would be triggered by the value on the integrator of the PID controller rising above a threshold. The amygdala of the brain may mediate this. Consistent with this, bilateral removal of the amygdala and hippocampus in monkeys is known to have a profound taming effect accompanied by hypersexuality, known as the Kluver-Bucy syndrome.

#36. Two Kinds of War [evolutionary psychology, engineering, neuroscience]

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Red, theory; black, fact

A Nazi Enigma code machine (Canadian War Museum)

There are probably two basic biological uses for human anger: dispersal, and providing an emergency brake on population increase that avoids Malthusian disasters by triggering wars. The second kind of war ends life without being notably efficient in producing mass migration. 

The Past

I have long wondered why the Four Horsemen of the Apocalypse seem to include two gentlemen in charge of warlike matters. Why the apparent duplication? The above may give the reason: one (with the bow) represents wars of depopulation and the other (with the sword) represents wars of displacement.

The Coventry Blitz produced so much mass migration into the countryside surrounding that city that it was an embarrassment for the British government, calling into question Britain’s willingness to fight. Was Coventry some kind of watershed, before which the conflict was of the displacement type, and afterward, of the depopulation type?

The facts bear this out, considering Nazi treatment of the Jews as a litmus test of the zeitgeist of that time. After coming to power in 1933, the Nazis aimed at forcing the Jews to emigrate, and by the outbreak of hostilities in September, 1939, 250,000 of Germany’s 437,000 Jews had done so. The Coventry Blitz was in November, 1940. The Holocaust began, in terms of men, women, and children all being targeted for execution, in August, 1941, nine months later. The German zeitgeist seems to have shifted gears in the fall of 1940, aiming at depopulation rather than displacement. I am obviously assuming that the evolutionary, selectionist justification of the Holocaust given at the time, in forums such as the 1942 Wannsee conference, was a rationalization.

A Sociological Theory

Wars brought on by population pressure may begin as the displacement type, and if this does not result in sufficient local reduction in population pressure after a certain time, the hostilities shift gears to the depopulation type of conflict. 

If human population is under PID [proportional-integral-derivative] control by the subconscious, the event causing the shift could be the amount of signal accumulated on the integrator rising above some threshold. This may actually be a second threshold, with the first and lower threshold controlling the outbreak of a war of displacement.

A paradoxical outcome of Calhoun's overpopulation experiments on rodents can be explained in terms of such an integrator. 

Calhoun’s Classical Experiment 

By providing unlimited food and water to a founder population of rats or mice, with regular bedding changes and exclusion of predators and parasites, the rodents were allowed to increase their population to fabulous numbers. However, the rodents were given no extra space. As the population soared to incredible densities, all kinds of pathological behaviors appeared along with a great deal of violence. Birth rates plummeted after a "behavioral sink" developed, and remained low, never recovering, as the population decreased all the way to zero.

An Engineering-inspired Theory 

My interpretation of the behavioral sink is that it is integrator windup, a pathology of humanly engineered PID controllers, and possibly natural ones too. The signal accumulated on the integrator has been building for so long, and the population crash is so sudden, that not enough time is spent at population densities below set point to cancel the "control debt" on the integrator, so it continues to insanely command a zero birth rate even as the population is heading for zero.

Philosophers May Have Noticed This

George Santayana wrote that "Fanaticism consists of redoubling your efforts when you have forgotten your aim." [source, Wiki quotes, accessed 06-11-2018] Which sounds like integrator windup to me.

The Future 

A third and highest threshold of the control debt may exist, which, if crossed, leads to the human behavioral sink and the possible destruction of the human race due to essentially psychological causes. In the behavioral sink, I postulate that everyone would be a ZPG (Zero Population Growth) fanatic and unable to change without pharmacological help. (Good old booze? It may not be that simple.)