I have this issue where I get really distracted and learn about random things, so let us dive into this. So today I ask the question, why have our brains gotten smaller over time? I would like to discuss and explore multiple theories as to why this happened.
My personal theory is akin to Moore's law. Moore's law refers to an observation made by Intel co-founder Gordon Moore in 1965. He noticed that the number of transistors per square inch on integrated circuits had doubled every year since their invention. As time passes, these chips evolve to be smaller and more efficient. Computer that once took up an entire room can now be held in our hands
So let us apply this to ourselves. Our evolutionary brain mass seems to be like a bell curve, gaining a lot of mass over the millenniums and then losing some mass more recently. As the brain grew and then shrank over thousands of years, its wiring became more efficient and specialized allowing for great strides in the development of intelligence. This is why we can claim we are much smarter than our ancestors who used to live in caves. As time passed, our brains got much faster and more efficient with processing information
Another theory is that as we evolved, we got into became more social and got into ever growing groups that eventually turned into civilizations. As we increased population density, our brains got smaller. Group thinking requires less individual thinking and more aggregation, think about sheeple (people who are less capable of individual thinking and have a herd mentality). Being sheeple, this may have led us to have our brains be reduced in size since less is needed to be allocated to our personal survival. However it may have allowed for individual specialization for humanity, leading to the development of things like things like the arts and sciences for example.
So while aggregate thinking has helped us, has it made us as individuals dumber? Or perhaps civilization can be compared to a multi-core processor that is reaching the end of Moore's law. Since it's reached the most efficient and smallest size through evolution, rapid change is no longer possible. Thus when we work together, does that accelerate aggregate progress of a civilization? I mean, look at our environment... everything here is a group project from the iPhone to research to even making a movie. It all exists because billions of people contribute, in their own way, to the movement of progress.
Language and capital punishment may have also led to rise of sheeple that reduced our collective brain size. It was our way of domesticating ourselves, making ourselves less aggressive by executing, jailing and banishment undesirable behavior. Perhaps this what led to the Pax periods in history through the formation of law systems that were similar to each other. This is also known as the Democratic Peace Theory which states that democracies are less likely to go to war with each other. Common law has brought less aggression and more peace to the world by conditioning humans to be more docile and socially acceptable. While all of this has brought less aggression and war in the world, did it also lead to smaller brains?
If you're interested in knowing more and want some actual scientific proof of what I'm talking about, check out this article by Discovery Magazine which explores in more depth what I'm talking about.
http://discovermagazine.com/2010/sep/25-modern-hum...