The Background to Human Intelligence

Human cognition has a history as long as humanity itself and has been vital for its success


A camping trip that lasted a lifetime

According to evolutionary psychologists **Leda Cosmides** and **John Tooby**, “Our hunter-gatherer ancestors were, in effect, on a camping trip that lasted a lifetime,” solving many different kinds of problems well to survive and reproduce.

As a result, they evolved physically and mentally to survive harsh conditions and take on the sorts of problems they were likely to be confronted with. The implications are that we are not born with ‘blank slates’ virtually free of mental content but that **we arrive evolutionarily-equipped with a selection of advanced information processing systems**.

After all, evolutionary psychologists see the brain as made up of evolved computational systems shaped by natural selection to respond to the environment with appropriate behavioral and physiological responses.

Such a view suggests multiple specialized adaptations equipped with context-rich representations and systems organized in such a way as to make sense and solve the problems of our hunter-gatherer ancestors.

The mind-body distinction?

There was a time when almost everyone considered the brain and the mind to be distinct. Indeed, philosopher René Descartes, a crucial player during the scientific reinvention that followed the Middle Ages known as the Renaissance, believed the mind was something immaterial – made of ‘thinking stuff’ very unlike the brain. Fundamentally, he believed that the physical and the mental were separate and unlinked.


Most scientists and psychologists now reject the notion that 2 fundamentally different substances are involved in our thinking. Instead, as ‘**materialists**,’ we accept that **our cognition results from matter and material processes**.

For some, such as cognitive scientist Steven Pinker, the ‘mind is what the brain does’ or perhaps more circular, the ‘mind is how the brain appears to itself.’
The result of recognizing that **there are no unique ‘mind processes’** is that we can explore thinking as part of the scientific method of investigating and understanding the brain and how it works.

Evolving such a powerful organ

Understanding human cognition almost demands that we take a step back and ask, ‘Why do we have brains?’ and ‘What are they for?’ But as Ukrainian-American geneticist **Theodosius Dobzhansky** famously said, “Nothing in biology makes sense except in the light of evolution.”

The brain has evolved as an organ, tripling in size over the past few million years, for decision-making, reasoning, perception, memory, and so much more. Our ancestors tracking kudu across the great African plains had to communicate with one another, solve problems, remember locations, and plan how to acquire their next meal.

Yet, **such a powerful organ has a cost**– the brain consumes somewhere between 20 and 25% of the body’s calories. Evolution had to balance the tradeoff between a powerful but power-hungry piece of mental kit and survival. This may explain, at least in part, why we are such good problem solvers but also why our mind sometimes fails us.

What is intelligence?

Researchers describe general intelligence as being good at a range of skills involving cognition, such as **planning, reasoning, and learning how to solve problems**. If you are good at one, you tend to be good at all of them.

Even being able to regulate and recognize our own and others’ emotions, known as ‘**emotional intelligence**,’ is considered a mixture of general intelligence and personality. And creativity, perhaps surprisingly, is no different – it requires intelligence to take raw input and turn it into something novel.


While we all wish for an easy fix when it comes to becoming more clever, it’s not that easy. Unless you’ve signed up to Kinnu, of course!

After all, studies suggesting that listening to classical music helps learning (known as the ‘Mozart effect’) are not easily replicated, and brain training systems often don’t deliver on their promises of easy learning.

Rather, the intervention most consistently linked to intelligence is an obvious one – education. Reading, studying, arithmetic, and acquiring new knowledge improves our concentration and benefits abstract thinking – and yes, Kinnu covers pretty much of all of them.

The importance of finding food

**Cognition, it seems, would have been paramount to our ancestors’ survival** and, therefore, the continuation of our species. After all, as Charles Darwin recognized, to reproduce, organisms must first survive.


One crucial adaptation was our ability to find food – the fuel necessary to keep our body healthy and acquire the energy needed to persist at living. The absence of food and water not only curtails an individual’s life but also constrains the group and species they belong to.

The need for sharing knowledge of hunting and food gathering, working together to return it to camp, and sharing out the bounty amongst the tribe would have driven cognitive complexity to ensure ever more advanced levels of communication.

Indeed, the division of labor among traditional societies can, in part, be explained by the acts of both hunting and gathering and appear underpinned by cognitive complexity. The challenge of finding food may have caused humans to have the most advanced communication systems of any animal.

A safe place to lie

On a modern camping trip, we typically know where we will stay. But imagine a camping trip that does not end, and where there is no option to jump in an air-conditioned car when it gets too wet or too cold.

Early humans needed to find somewhere to rest at the end of each day, protected from wild animals and other tribes, close to water and food, and yet away from environmental hazards like floods or cliff edges.
The ‘Savanna hypothesis’ suggests that selective evolutionary processes working on our brain would have favored preferences, motivations, and decisions, facilitating and encouraging us to settle in environments abundant with resources necessary to sustain life.

Such a theory may go some way to explain why countless studies have shown our present day preference for natural, seemingly safe, resource-rich environments when confronted with a selection of photos to choose from.

Fear – a powerful bias

While the feelings associated with stress are often unwelcome, they are sometimes justified by the situations we find ourselves in or result from an inherited legacy of the dangers we, as a species, once faced daily.

Indeed, **listening to our intuitive fears may often provide a valuable guide for assessing risks and directing our cognitive processing to avoid a threat**. While we are all aware of ‘**fight,**’ ‘**flight,**’ and ‘**freeze,**’ there are other intuitive responses.

Three further, often highly automatic, brain-led reactions include ‘**submit**’ where we yield to another, ‘**fright**,’ literally playing dead, and ‘**faint**’ losing consciousness – all of which can signal to a would-be attacker that we are not a threat.

Whether under our conscious control or not, **brain processes kick in and offer protection when most needed**. The unwanted side effect is that they can introduce bias into our thinking, reasoning, and motivations that are no longer appropriate to the world in which we now live.

Is it all in the genes?

Research using twins confirms that approximately **50% of the intelligence difference between people is due to genetics.** Vast studies and powerful computers highlight the importance of our parents, our parents’ parents, and so on.

And yet, while genes matter, so too do environmental factors, such as the quality of our children’s diets, how much time they spend exercising, whether they have access to good education, and the amount of time spent playing. And yet, the links are not always as clear as we would like because they involve several overlapping factors.


**The remaining 50% offers us opportunities to change our intelligence**. Indeed, increasing understanding of our ‘**neuroplasticity**’ within the scientific community confirms that, far from our brains staying fixed, we are born with potential. This means that we can surpass our genetic trajectory.

And clearly, we must be doing something right. A 2015 study across 48 countries found that IQ scores resulting from standardized intelligence tests have increased since 1950 by a whopping 20 points. However, there is a flip side. It seems that, **as we age, our working memory drops**. And that’s a problem because it helps us manipulate information and solve problems.

How we evolved extraordinary human intelligence

Our brains are enormous relative to our body size – even when compared with our closest primate cousins. In turn, we have unparalleled capacities for abstract thinking, visualizing, learning, and problem-solving.

But **why did we evolve such extraordinary human intelligence?** The **‘Ecological Dominance/Social Competition**’ (EDSC) hypothesis suggests it came into being to combat the hostile forces of nature faced by our distant relatives – and ultimately help ensure their survival.

The theory recognizes the incredible value of living in social groups and the importance of forming coalitions, detecting deception, and even dishing out punishment. Relationships essential for hunting trips, along with the underlying psychological adaptations, would also have been valuable in securing support for fighting and warfare.

Such a social hypothesis also predicts the need for greater intelligence as living groups become more extensive and population density increases. Surveys of early human skulls and analysis of archaeological evidence of increasing population sizes appear to show an increase in brain volume associated with larger groups living together.

Ingenuity may place increasing general intelligence at risk

Human cognition and creativity are not without risk. Indeed, **Linda Gottfredson** calls out that the invention of tools such as fire, weapons, and even canoes created novel hazards for our ancestors.

According to Gottfredson’s ‘**deadly innovations hypothesis**,’ while such development may have offered dominance over the environment, they increased the risk of injury and premature death, creating additional selection pressures for the evolution of general intelligence.

Indeed, according to what’s been called ‘**double jeopardy**,’ the less intelligent are at greater risk of dying when using such tools. Subsequently, their children have increased mortality due to their parents’ inability to offer protection.

Empirical support has added weight to this argument. One such study identified that **each additional IQ point leads to a 1% reduction in the relative risk of death**. In our modern, technologically advanced world, those with lower scores on intelligence tests are more likely to die from falling objects, knives, bicycles, and explosions.

It seems that, **while innovation brings with it many benefits to the individual and the group, it also introduces new dangers**.

You will forget 90% of this article in 7 days.

Download Kinnu to have fun learning, broaden your horizons, and remember what you read. Forever.

You might also like

Introduction to the Brain;

The complex nature of the brain and the tools to help us understand what’s going on inside

Problem-Solving, Expertise, and Judgment;

Our ability to survive and thrive relies on overcoming obstacles and solving problems in everyday life

Perception and Motion;

Our ability to move while perceiving the environment has always been crucial to individual success and our survival as a species

Knowledge Representation and Memory;

Understanding what it takes to remember and recall what we need to survive and thrive

Understanding Language;

To fully comprehend what is being said, language processing takes place at multiple levels, breaking down both meaning and structure

Language Production;

Our human ability to share what we are thinking requires complex planning and production processes

Leave a Reply

Your email address will not be published. Required fields are marked *