Ideas, Intuition and Thinking

A Brief History of Your Brain

Part 1 - What the Human Brain Evolved To Do

Part 2 - How Humans Changed How They Used the Brain 

Most of my life I have been fascinated by the power of ideas and how human brains develop them. When I look at a well designed teapot, see a better way of organising business, or a new way of putting pieces of information together to solve a problem, I think of the person who worked it out and the processes of the brain that led to it.

During the past half century cognitive scientists have given insights into how the brain handles information. Their experiments have revealed a long list of cognitive errors that the human brain is innately predisposed to make. The human brain is attracted to plausible arguments that sound right, even if they do not stand up to logical analysis.

Every idea has a proposition based on underlying assumptions which may be implicit and unrecognised. This website analyses some big ideas and puts their logic and underlying assumptions to the test.

Major propositions of this website

• the human brain evolved during 6 million years among hunter gatherer ancestors 
• the human brain did not evolve to think. It evolved to make humans and their hominid ancestors expert hunter gatherers
• humans in the modern world use their brains in ways their brains did not evolve to be used to produce very different lifestyles
• different societies use the mechanisms of the brain in different ways to produce different economic and social outcomes
• the basic mechanism of the brain that evolved to preserve hunter gatherer practices continues to operate in the modern world to perpetuate cultures, social attitudes and beliefs.

A major feature that distinguishes the modern world has been the torrent of ideas and innovations that has made change a constant in modern lifestyles.

The burst of innovation in the modern world is in stark contrast to all previous eras of human history.

Almost all of the ideas that define the modern world were developed within the last 300 years, most within the last century.

Hominids - First in the Human Ancestral Line

The human line split from apes when climate change more than 6 million years ago slowly turned forests into open savannah. Hominids were the first in the human ancestral line, no longer apes, but not yet human. Their survival required the first of three major changes in the use of the brain that defined the path from apes to modern humans. Over the next 3.5 million years they developed a hunter gatherer lifestyle.

Hominids and later humans lacked sharp teeth or claws with which to hunt or defend against attack. They compensated for internal weakness by using external objects such as pieces of stone, bone or wood as tools and weapons, requiring them to stand on two feet, freeing up their hands. There is no evidence that they used their brains to work out how to modify any of those objects to produce better tools or weapons.

The Basic Mechanism of the Brain

The mechanisms of the human brain evolved over 6 million years among human ancestors who had not evolved speech. Their brains evolved to store scenarios as visual images of situations that included automatic responses. Their lack of physical strengths meant that, more than any other species on the planet, hominids relied for survival on the range and flexibility of their behaviours. Constant survival pressure on individuals lacking an adequate range of behaviours produced the conditions for evolution of a larger brain. Most of the increase in size of the human brain has been in non-conscious long term memory, used to store more scenarios to produce a greater range of automatic, expert responses.

Mammalian brains evolved a small conscious short term memory as a slower, less reliable backup when existing scenarios failed to produce a suitable automatic response. This backup enabled humans to modify automatic responses to suit specific conditions, or to work out new responses for unfamiliar situations. The lack of innovation through millions of years of human evolutionary history shows the limited use of the backup.

The basic mechanism of the human brain evolved to learn by observing how experienced members of the group handled situations, storing knowledge in the brain as scenarios. It evolved to perpetuate with great fidelity past practices that had made human ancestors successful hunter gatherers. For millions of years the conservative nature of that mechanism inhibited innovation.

The First Humans

When the first humans with a larger brain evolved more than 2 million years ago, their main innovation was to chip pieces of stone to shape them into tools and weapons. That innovation produced the Stone Age - the Paleolithic. For the next 2 million years humans continued to live the hunter gatherer lifestyle.

Modern Humans

Modern humans with the ability to speak and to communicate complex concepts evolved more than 170,000 years ago. For the next 160,000 years the main innovations of modern humans were better stone tools. They continued the Stone Age, living the hunter gatherer lifestyle developed over the previous 6 million years.

The Second Major Change in the Use of the Brain

Things changed just over 10,000 years ago, when humans in what is now called the Fertile Crescent were forced to change their lifestyle in order to survive a sudden drop back into a mini-Ice Age. They began to herd animals they had previously hunted and to farm crops they had previously gathered in the wild.

That change in lifestyle required the second major change in the use of the brain. That change required humans to make greater use of conscious processes of the brain. That was the start of the New Stone Age - the Neolithic.

When humans domesticated animals and plants, they domesticated themselves. Farming required humans to settle on land. Settlements became towns, in which some people developed specialised skills, producing new items such as pottery and metal objects.

For the first time in millions of years humans accumulated possessions in the forms of livestock, produce, pottery, metal objects, jewellery and ornaments. The change in lifestyle created the first wealth in human history. When growing populations of humans began to trade produce for these items they created the first economies.

The First Cities and the Beginnings of Complex Societies

A long, hot, dry spell just over 6,000 years ago pushed growing populations to concentrate into fertile river valleys, creating the first cities with the first signs of central administrations and organised religions. That was the beginning of complex societies and the search for a workable method of organising them.

The first cities also had the first fortifications, a sign that humans quickly worked out that one way to accumulate wealth was to plunder someone else’s.

From the beginning of complex societies, power was concentrated into a ruling group headed by a monarch, whose critical role was to command armed forces to assure security and to attack enemies. Throughout the 6,000 year experiment with complex societies the most common form of rule has been monarchy. Presidential systems that developed in the 18th century replaced an hereditary monarch with a monarch elected for a term.

Millions of years of human evolution and thousands of years of experimentation with complex societies provide evidence that brains did not evolve to think. Human brains evolved over 6 million years among human ancestors who lacked speech. They evolved to learn by observing and non-consciously absorbing and storing records of existing practices as scenarios. We can see that mechanism at work in young children whose brains are like sponges that learn by observing what is happening around them.

When situations arose, the brain evolved to recognise similarities with its stored scenarios, which then provided fast, automatic responses. The basic mechanism of the brain evolved to have things worked out in advance, producing expert actions and responses automatically, without the need for conscious thought.

The conservative nature of the basic mechanism of the brain kept humans in the Stone Age for millions of years. It continued to inhibit innovation for most of the 6,000 years during which humans have been experimenting with complex societies, until the effects of the third major change in the use of the brain began to show up in recent centuries in the innovations that led to the modern world.

The mechanism that evolved to pass on automatic, expert behaviours to our hunter gatherer ancestors operates in the modern world to pass on cultural behaviours and attitudes from generation to generation. It is the source of intuitions, hunches and "gut feelings", based on observations accumulated in the brain, many of them absorbed with little or no conscious thought or awareness.

The Third Major Change in the Use of the Brain

The burst of ideas and innovations in recent centuries has come from a different way in which humans in Northern Europe used their brains. As agricultural practices that had been developed for temperate regions spread to northern regions, humans living there had to work out their own ways of doing things to enable them to survive through ice-bound winters.

For millions of years humans had existed as part of small social groups, the survival of which relied on each new generation learning the practices of earlier generations and passing them on in turn to following generations. Survival through the extremes of northern winters often physically cut off human interactions for long periods, forcing people to be self reliant. Individuals had to plan their own survival. That self reliance shows up today in individualism that distinguishes western cultures.

When humans in northern Europe treated themselves as existing independent of the social context, they also treated other entities as being separate from the contexts in which they existed. Individuation of objects in mental records has enabled humans from western backgrounds to make different connections among objects that produced innovations that led to the modern world.

Reducing contextual connections among entities also produced Neglect of Context, a form of Fundamental Attribution Error that cognitive scientists have identified as the most common error of the human brain, particularly among humans from individualistic western cultures.

Replacing Instinct With Intuition

The basic mechanism of the mammalian brain evolved because species with instinctive behaviours hardwired at birth were subject to extinction when the conditions to which their behaviours were adapted changed and their hardwired behaviours did not enable them to survive the new conditions.

The mammalian brain replaced instinctive behaviours with intuitive behaviours that had proved that they worked because they were absorbed from individuals who had used them and survived. Behaviours that did not work were eliminated when individuals who used them did not survive and they were no longer available to be observed and perpetuated.

The mammalian brain also evolved a small conscious thinking capacity which modified automatic responses to suit specific circumstances, or worked out a new response if traditional responses were no longer effective. New or modified responses were preserved by that same mechanism, passed on to future generations by observation and non-conscious absorption.

 Short Term Memory - the Bottleneck on the Brain

Since the change of life style 10,000 years and in complex societies that have developed over the past 6,000 years, humans have made increasing use of conscious processes. Short term memory with the capability for conscious thought that evolved as a peripheral brain function, is used by modern humans as a major function of the brain.

In 1900 one of the founders of psychology, Sigmund Freud, drew the world's attention to the existence of what he called the Unconscious. In 1956 one of the founders of cognitive science, George Miller, revealed the tiny capacity of short term memory. Miller described it as a bottleneck on the brain. It is not a bottleneck on automatic responses. It is only a bottleneck on conscious processing, providing evidence that the brain did not evolve to have conscious processing as a major function of the brain and that humans in the modern world use their brains in ways that brains did not evolve to be used.

These ideas have been set out in more detail in my book Connecting the Dots.

Every proposition contains underlying assumptions, which are often unspoken and unrecognised. My blog tests the logic used to develop ideas and their underlying assumptions.

The first idea examined will be Darwin’s explanation of the evolutionary mechanism, which American philosopher Daniel Dennett described as ‘the best idea, ever’. Darwin’s central idea was sound, but his explanation was wrong.

Darwin's explanation was not based on scientific need. It was based on cultural attitudes that Darwin undoubtedly regarded as observable truth, rather than subject belief. Unfortunately, the biological sciences have constructed their basic assumptions on Darwin’s explanation. My blog will point out why the biological sciences need to go back and recheck their assumptions.

My blog will force you to think. If you are up to dealing with arguments that will challenge your neurons, subscribe here. If you do subscribe, feel free to suggest ideas or beliefs to analyse and challenge.