We humans sometimes describe ourselves as the big-brained ape. Gorillas and even chimpanzees have more powerful muscles and sturdier bones than we do, but we're the species with the capacious cranium.
This is true, as far as it goes. Our brains are three to four times bigger than chimpanzee brains, and bigger than gorilla brains, despite our bodies being only a third the size of gorilla bodies. Since we branched away from the great apes a few million years ago, our brains have quadrupled in size.
But something strange happened on the way to the present. About the time our ancestors became civilized—that is, built cities and lived in large groups—our brains got smaller. Anthropologists have found a decrease in brain size by about 10 percent between 5000 and 3000 years ago. Brain size stabilized after that, leaving us at a permanent disadvantage to our prehistoric ancestors.
What happened? Nobody knows for certain, but it seems to have something to do with smart phones.
Okay, not exactly. Not in a linearly causative sense. But in the sense that both reflect a communalization of human intelligence.
Here's the anthropologists' explanation. In their pre-civilized state, humans had to be self-reliant. They had to be able to solve their own problems, defend themselves against all kinds of threats, master the lore of the natural world, stay one mental step ahead of both the creatures they were preying on and the creatures that would prey on them. To borrow a term from a much later era, their brains had to be all-purpose computers. Humans didn't know how to store knowledge outside their own brains, so their memories had to be large.
With civilization came specialization. Soldiers had to be soldiers but not also hunters and gatherers. Farmers had to know their crops and the seasons that affected them, but they didn't have to know the ways of deer and turkeys and fish. Writing relieved the memory burden; individuals didn't have to remember the whole history of their societies.
Brains are expensive to operate. The average human brain consumes a fifth of all the energy a body burns in the normal course of a day, despite being only a fiftieth of body mass. People with smaller brains required fewer calories. Under the new circumstances of social specialization, the smaller-brained individuals were not at a selective disadvantage to their larger-brained contemporaries. So the thriftier, smaller brains thrived and gradually displaced the larger ones. Societies got collectively smarter, but individuals got stupider.
That's the theory. At this late date, it's pretty hard to prove something that happened so long ago. We can spot the correlation; we can't be sure about the causation. And not all anthropologists are confident the brains actually got smaller. The sample sizes aren’t large, and human skulls, which are the things actually measured, vary from individual to individual. Moreover, smaller brains might have become more efficient.
Yet it sounds plausible. And it would seem to have implications for the present, in particular our increasing reliance on portable computing technology. In the last 50 years, humans have gotten demonstrably stupider in certain categories of intellectual endeavor. Before pocket calculators, every student by 5th grade had the multiplication table up to at least 12 times 12 by heart. These days no one bothers. Every phone is a calculator; every pocket has a phone.
The ability to spell words correctly used to be a mark of an educated person. Spelling competitions persist, but they’re a polite version of freak shows. Spell-checkers have rendered orthographical expertise obsolete.
Boy Scouts weren't the only ones who learned how to read maps; it was a skill required by anyone who ventured away from home. Smart phones now guide us to our destinations without requiring any more of us than the ability to turn left or right on command.
All this is not intended as a lament for a golden age. Nor is it a screed against excessive reliance on computing devices and their interconnections. To call for a return to the earlier time is a bit like saying we should revert to hunting and gathering. If we tried that, most of us would starve. We’ve come too far down this road to turn back.
Yet it is something to consider as we leap into the brave new world of artificial intelligence. To date, our computers calculate for us and extend our memories. But when they begin to think for us—to make choices based on information beyond what any individual can process—we might really get stupider. If I can’t multiply 8 times 9, if I can’t spell, if I can’t find my way to a restaurant, civilization won’t crumble. But if I can’t make decisions—if we outsource the decisions that will determine the fate of our species and our planet—civilization might by then already have crumbled.
An old trope of science fiction was the brain in a bottle, the body having evolved into disuse. Maybe the trope had things just backward. And maybe this is a lament after all.
This debate over whether technology makes us more stupid has been waged for at least 2400 years.
Plato wrote (in Greek) in his dialogue “Phaedras” about Socrates’ expressing his concern that the invention of writing would cause people to lose their ability to remember things. Plato says Socrates said, "This discovery ... will create forgetfulness in the learners' souls, because they will not use their memories; they will trust to the external written characters and not remember of themselves ... [Writing will] give your disciples not truth, but only the semblance of truth; they will be hearers of many things and will have learned nothing."
On the other side, often quoted, Albert Einstein supposedly said, "Never memorize something that you can look up." There is some debate about whether Einstein actually said this. However, in a 1936 essay, Einstein did write: "It is not so important to know an answer as to know how to find it." This writing is often interpreted to mean that it is better to focus on understanding concepts and how to find information, rather than memorizing facts and figures, revealing his philosophy of education and his belief in the importance of critical thinking.
As an aside, although Einstein wanted to be cremated on his death in 1955, and most of him was, the pathologist, Thomas Harvey, could not bring himself to allow that brain to turn to ashes and dust, so he removed and pickled it, carving out some portions of it and mounting them onto microscopic slides that he sent to others to study, retaining most of it for himself to investigate, and later to be given by his son to the Princeton University Medical Center where it resides today. Harvey damaged portions of the brain in removing it from the skull and the formalin pickling juice caused what was undamaged to shrink, so it is difficult to know whether his brain was larger than average, whether it was organized differently than those of the rest of us, whether the parietal lobe was larger, whether it had more or less neurons in certain nuclei, or whether his dyslexia required or allowed his brain’s plasticity to develop strong visual and spatial reasoning abilities.
While Stephen Hawking was already an accomplished mathematician, theoretical physicist and artist before he developed Amyotrophic Lateral Sclerosis, its onset and progression required his brain to strengthen its visual and spatial reasoning abilities.
One thing we do know is that brain activity increases its interconnectivity in the areas of those activities. Areas of inactivity reduces those connections.
So the question is not whether we will become “stupider” as machines take over functions heretofore required of our brains for our specie’s survival and becoming what we are today, but whether those activities will be missed and the relative value of what will be gained compared to what will be lost.
Critical thinking skills will still be required, even need to be strengthened, if we are to know where to look for information and to evaluate whether what our machines retrieve is from credible sources or questionable ones.
The spelling aspect (and subsequent competitions) seems to really only have been an issue once dictionaries began standardizing word spelling. One can find words spelled quite differently from the current times back to the 1700s. A prime example is "choose" in which I have seen writings from 200-300 years ago use "chuse"