My phone keeps filling up with applications and songs and videos, until it starts running unbearably slowly. The Internet gives me the following advice:
“If your phone accepts external storage, buy a micro SD memory card for it.
That will give you an instant boost, and it’s a relatively cheap method of expanding your phone’s capacity”
Hmm. We’ll come back to my phone problems later.
For some, it’s comforting to consider how similar humans are to other animals, how we fit into the fabric of the natural world. But sometimes I think, sorry, this is just nuts. We are completely different from other animals. Look what we’ve done to the world. Jet planes, men on the moon, skyscrapers, TV, the Internet, Dolly Parton, a lot of plastic. Astrophysics. Astrology. Shakespeare, Monty Python, Dan Brown. We just do things other animals don’t do. If we are so similar to gorillas and chimpanzees, why don’t other apes have legal contracts, sports teams, fashion shows, and awards ceremonies?
This brings us to a puzzle. If we look back to the origins of modern humans – the evolutionary path from tree-dwelling primates, to Australopiths, Homo habilis, Erectus, Ergaster, Hiedelbergenis, and to Homo Sapiens over millions of years – we see a gradual increase in brain size, from the size of an orange to a melon. If we follow the evolution of culture, based on the archaeology of tools, evidence of group social activities, cultural artefacts and cave paintings, we see increasing complexity. But the rate of change doesn’t match up at all. The gradual increase in brain size – conveying the advantages we talked about in the previous section – took 3 million years. Most of the increase in cultural complexity has occurred in the last 100,000 years, with an exponential increase in the last 8,000 years.
To sense that acceleration, think of my phone. Humans started to count perhaps 50,000 years ago. Calculating devices were invented around 2,500 BC. Mechanical calculators were invented in the 1800s. Digital computers were invented in the 1940s, the Internet in the 1970s, touchscreens shortly after. Smartphones sit atop all these inventions. Now, there’s a new iPhone model each year! And over this period of history, human brain size has hardly changed.
Look back to archaeological time, and you can find large stretches of time when the brains were getting bigger but culture and tool use didn’t change at all – for, like, half a million years! We can only conclude that big brains are necessary for tool use and culture, but not enough.
Peer into archaeological time, and you see physical changes as homo species follow each other, from tree dwelling to bipedalism, along with increasing brain size; but tool use and culture show staccato changes and long periods where nothing happens. It’s a puzzle.
It probably needs a lucky combination of circumstances to get cultural innovation off the launch pad. Something like: big enough brains; enough humans hanging out together; enough resources to keep everyone fed; tool making abilities; social co-ordination; language abilities; teachability and willingness to learn. But perhaps the most important is the invention of information tools. These are artefacts that can convey information between individuals, so-called symbolism. When knowledge can be recorded, shared, passed on, in writing, symbols and pictures, there are the conditions for knowledge to accumulate across generations, and to be improved upon.
It works a bit like this: John figures out a plan for making bricks. John’s son, John-son, looks at the plan years later and realises that with bricks you can build a wall. His son, John-son-son has the insight that if you combine the walls with a roof, you can make a single story building. John-son-son-son figures out that with stronger bricks and supports, you can make two-storey building. And so on. Each generation can improve on the plans of earlier generations (so long as the plans are not lost!). This virtuous circle of accumulation depends on information tools. Things could have probably gone quicker if John had had daughters.
No doubt there were some false starts getting this process off the ground for humans. The accumulation of knowledge may have sputtered out in some cultures. Maybe other species could have managed to get cultural accumulation going, like Neanderthals, but the lucky combination of circumstances didn’t occur. But in humans, it has gone stratospheric.
When we create tools, especially information tools, we extend the mind beyond the brain. That sounds spooky. But think of my problematic phone. When I add extra memory to it, the phone’s functionality gets a boost. It gets smarter. Is the memory card part of the phone or not? When I use a notebook, I am much better at arithmetic, because I don’t have to keep all the numbers in mind. Is the notebook part of my mind or not? When I do a crossword, I scribble ideas and partial answers in the margin of the newspaper. Is the newspaper part of my mind or not? Maybe the answer doesn’t matter, only that when I can scribble on paper, I am more effective at solving crosswords.2
The more complicated and powerful our information tools, the smarter we get. The Internet. Tablets. Virtual reality. In a sense, we become as clever as the machines we create. While the brain is restricted, the mind can be extended.
We raise our children in the cultural environment of the current set of tools. This changes how their brains develop – albeit in ways limited by the flexibility of the underlying biology. When we learn to read – through arduous practise – experience modifies parts of the visual system, causing a part of the brain to specialise in recognising print. 3 When we learn mathematics, multiple brain areas have to be encouraged to work together to integrate number symbols, quantities, object relations, scales, quantities, calculation, and all the links between perceptual information and motor procedures that go with them. Tools change the brain processes we use to complete tasks: the availability of Google may lessen educational pressure on memorising and retrieving facts, and the brain structures this employs, and increase expertise on plans and procedures for using the ‘Google’ tool to unearth information on the Internet.
Culture creates tools, but it can also create modes of thought. These can be similarly trained through education. For example, ‘logic’ is an invention of culture that occurred only 2,500 years ago. Deductive logic (i.e., what arguments are valid, If A then B, A, therefore B, etc.) had to be deliberately separated from rhetoric (attempts to persuade people through argument). This distinction was made by Aristotle in ancient Greece. How did he come up with the idea that reasoning should be separate from argument? Cultural innovations can have obscure or chance origins. The inspiration for drawing the distinction probably arose from the particular socio-cultural and political conditions in ancient Greece at that time. 4
With the brain’s conceptual power, we can literally imagine we are computers. We can run mental simulations of how our information tools operate. And with practice (as is the brain’s preference) such a skill can become automatic. When we think logically, this is what we are doing. Computers (unthinkingly) manipulate symbols that stand for things, not caring what the things are. The 20th Century mathematician and philosopher Alfred North Whitehead pointed out that the type of mechanical reasoning that computers do is the dumb part of thinking: “By the aid of symbolism, we can make transitions in reasoning almost mechanically by the eye, which otherwise would call into play the higher faculties of the brain.” 5
The quote emphasises that the normal mode of operation of the brain is not logical and deductive. The human brain, appropriately trained and deploying cognitive control, can operate in a way that is rationale, logical, scientific, rule following, and law abiding, based on presumptions of literal truth, clean-cut definitions of concepts, and black and white boundaries between what is right and wrong. By contrast, in the way it works, the brain doesn’t like to abstract; it likes to be based in the concrete, influenced by what’s familiar and what’s likely to happen; its ideas are painted in shades of grey; it is influenced by context, settings, and goals; it’s a social and emotional device that is prone to give in to peer pressure (what most people believe) and to trust authority figures; it’s influenced by anticipated rewards and losses; it gets tired and it gets irritable. It interrupts long lists to say now is a good time for a cup of tea.
The modern brain we see today may have taken millions of years to evolve, but its detailed functioning is shaped by the educational environments, tool sets, and social customs generated by mere millennia of cultural accumulation. And iPhones. 6
 Paul Howard-Jones, 2014, “Evolutionary Perspectives on Mind, Brain, and Education”, Mind, Brain, and Education, 8(1).  See Andy Clark’s book, see “Supersizing the Mind” (2010, Oxford University Press)  See Stanislas Dehaene’s book Reading in the Brain  See Michael Shenefelt and Heidi White’s book “If A then B: How the World Discovered Logic” (2013, Columbia University Press)  A. N. Whitehead (1958). An Introduction to Mathematics. New York: Oxford University Press. Chapter 5. 61. (See Shenefelt and White, p. 232, for lucid discussion).  Here’s a book by Cecilia Heyes, Senior Research Fellow in Theoretical Life Sciences and Professor of Psychology at All Souls College, University of Oxford, investigating these ideas in more detail: Heyes, C. (2018). Cognitive Gadgets: The Cultural Evolution of Thinking. Harvard University Press. Heyes proposes that humans have gadgets (‘small mechanical or electronic devices or tools, especially ingenious or novel ones’), whereas we have argued that they have gizmos (defined as ‘a gadget, especially one whose name the speaker does not know or cannot recall’).