Losing a Lime
I just read in the Wall Street Journal that researchers have been working to understand why the average human brain has been shrinking in the last millennia or so. There is an old joke about the dinosaur speaking at a convention of other dinosaurs. He says to the group, “The outlook is not good gentlemen, meteors have been striking the earth, the climate is changing for the worse, vegetation is disappearing…and we all have a brain the size of a walnut!” Biologists have always used the working assumption that evolutionary development created humans with larger and larger brains as they evolved. That was the case for evidence uncovered for over 2 million years, during which the human brain grew by almost four-fold. But empirical evidence was giving us conflicting data that showed that the human brain has been shrinking for the past 3,000 – 5,000 years. There has been a a 10-15% brain volume reduction during the most recent epoch. The scientific community has determined this by mining fossil remains. That is a significant change that has been characterized as the equivalent of the human brain losing a volumetric amount of its mass equivalent to a good-sized lime.
In searching for an explanation for this meaningful change in brain size, anthropologists initially speculated that this change coincided with the societal shift from hunter/gatherer life to agricultural life, the thinking being that farming was a less stressful and more peaceful way of life that did not require our prehistoric predecessors to keep as many wits about them moment to moment as they needed to during the hunt. But then, through the study of insects, specifically ants, a new theory began to emerge. Ants form cooperative “societies” where they operate on an “ultrasocial” basis where things like division of labor are optimized with little or no individual realization and all of the colony operates on the basis of the collective or common good. It seems that approach finds that smaller-brain beings (ants) are better adapted to this form of collective endeavor and having too big a brain is more of a liability than not. The secret is the creation of advanced social organizations that are very ordered and governed by rules or laws that are deeply ingrained in the individual beings involved. That’s right, ants do better by following the ant colony rules and their smaller brains make it less likely that they will break those rules by overthinking their individual roles.
A few years ago we had a serious infestation of small red ants which are called Argentine Ants. They are an especially successful and invasive species which has been so successful that they have expanded their colony all the way from Argentina up through Latin and Central America into the Continental United States and even as for north as Canada. The interesting thing to us was to learn that the billions of Argentine Ants that inhabited the 7,000 miles of the north/south Western Hemisphere are all from one single colony. I’m going to guess that keeping brain size in check and having a no-nonsense policy towards sticking to the rules of the colony are what have made that colony as successful as it has been.
If scientists are correct in looking to ant colonies for an answer to justify the shrinking size of the human brain while we humans have evolved from fierce but limited individualism to more intelligent collectivism. The thinking is that we, as collective beings, need not store all the information needed to survive and thrive by ourselves, but have learned the value of relying on one another to both improve efficiency and thereby free our brains to shrink while increasing collective success of our society. Another big contributor could also be the advance of technology in the storage and access of vital information. From something as basic as books all the way to immediate access to vital information via the internet. Its clear that we as humans have created lots and lots of memory prosthetics that clearly reduce the need to dedicate ongoing brain-share to information that can be readily accessed. And then too, there are tools like calculators, computers and the expanding array of robotics and AI that give rise to some combination of expanded mental capacity or reduced need for brain space.
But brain size does not necessarily indicate intelligence. The brain uses 20% of all bodily energy to operate properly, so energy efficiency really does natter and neurologists now know that intelligence depends less on brain size than on brain density or thickness (making me wonder why being “thick” is a bad thing) as well as aspects like the neural networks that control the brain, which is not size-dependent. The average brain size is 1,325 cubic centimeters and the brain size reduction has been about 150 cubic centimeters. Science has a habit of saving the brains of very special and talented people in the off-chance that something can be gleaned from it. It is noteworthy that Einstein’s brain is smaller than normal, so the notion that size alone matters is a non-starter.
One of the biggest issues in ethics and, consequently, in political policy discussions is the ever-present balancing act between individual liberty versus the common good. If you can agree on what constitutes the common good then you can start to address the value of the collective versus the individual. Few concepts are more highly charged in today’s political dialogue. There is plenty of evidence, both anecdotal and empirical, to suggest that the collective underperforms societies with a prevalence of individual initiative and freedom to act. But performance has many metrics that have to be weighed. In economics, we think in terms of maximizing utility and that generally encompasses everyone in the society. Maximizing GDP means little if that GDP is neither sustainable enough not distributed enough to allow for further gains through the economic multiplier effect that is more prevalent in collectivist systems than individualistic ones.
Thanks largely to the abject failure of Soviet communism, collectivism has perhaps unfairly gotten a bad name. The nastiest accusation you can fling at an American is suggest that they are a socialist, and it is a favorite dig at progressives by conservatives. But the truth is that for thousands of years, man has moved more and more towards greater reliance on collectivism in everything from defense to infrastructure. In fact, it is fair to say that the existence of government of any kind is a nod to the value of collectivism. And who can or wants to live without any government (other than perhaps Elon Musk)?
Nature has a way of telling a tale with a high degree of certainty. Nature is telling us now that the human brain is optimally gearing itself to the necessary collectivist reality that an 8 billion person world demands. We needn’t think of this as the dumbing down of mankind, but that mankind needs to be more and more efficient to deal with the realities of today’s world. I would argue that we not only can afford to lose a lime’s worth of our active grey matter, but that we must streamline our thinking to serve the greater good of humanity.