We, human beings, are responsible for creating so many things that we got used to them. We consider our achievements here on the planet as if they were a natural part of it. We rarely – or never – realize that almost everything around us is the result of the work performed by the persistent, creative, and restless human species. Walls, electrical wires, architecture, complex systems, languages, just look around. It is extraordinary to see what humanity has achieved together.
BIOLOGICALLY SPEAKING, WHAT MAKES US SO SPECIAL?
Which brings us to the question: on a planet with so many species, how did we humans get so far? If we are just primates, simply one more animal in the world, how did we, scientifically speaking, gain this ability? Simplifying this idea is really tempting. We want to imagine that it was only a matter of evolution. We humans are the best example of evolution on the planet, and full stop. However, the answer is a little more complex – and wonderfully curious – than that.
For a long time, scientists thought we differed from other animals in some abilities that we thought were only ours, such as the concept of numerical quantities, the recognition of abstract patterns, the use of symbols such as language, the use and creation of tools, empathy and the ability to lie and cheat. But when these properties were studied, we saw that we are not the only ones here on earth to have them. Some species of birds, other primates, and even mice also have these abilities that we thought were inherently human.
If we no longer have such exclusiveness, how did we get here? Recent studies on the subject, which involve more detailed brain investigation, have demonstrated that we no longer need to think of exclusiveness, but should otherwise begin to understand ourselves through the whole, or the combination of two elements: biological ability and learning ability. Our biology and our ability to learn and convey knowledge in an organized way were the two elements that when combined helped us get here.
BIOLOGICAL ABILITY AND WHAT OUR NEURONS HAVE TO DO WITH OUR KITCHENS
For many years, it was believed that species whose brain was similar in size had the same amount of neurons. However, we found out that in more complex species, such as primates, the evolution happened and the number of neurons increased while the brain size remained the same. Then, it was no longer the brain size that drove the evolution, but the brain ability.
In other words, what biologically sets us apart from all other animals is the number of neurons we have in our cerebral cortex – the top of the brain, which enables much more than just detecting stimuli and responding to them. That’s where our self-knowledge abilities lie and our ability to look at ourselves, think about what and why we want to achieve something. Problem solved: we, humans, have the largest number of neurons among all species.
Of course, it still doesn’t answer the basic question: why us? Some studies with other primates help us clarify this aspect. They found out that during the thousands of years of evolution, other primates failed to reach a more complex brain simply because of a physical issue: they had reached the limit of what a body could sustain in terms of energy and metabolism. In short, keeping billions of neurons active burns many calories! For example, to keep up to 53 billion neurons active in a lean body of 25 kg, a primate with a body built to consume the food on which it usually feeds should spend 8 hours a day eating. To have a body larger than 25 kg, this primate would have to give up neurons, or else it would have to spend the day eating, which would make survival unfeasible.
It seems that what has changed our history of evolution was the development of a seemingly simple habit: we started cooking our foods. After all, cooking is nothing more than pre-digesting food, which has made it easier for us to adapt the consumption of calories over time, allowing us to consume more calories in a shorter time. That is, we can’t underestimate the role of the kitchen in defining the biology of our species.
This paradigm shift has led us to the culture of agriculture, a civilization with division of tasks, the market, invention of electricity… and to the present day, where a simple snack heated in a microwave oven can assure more calories than we need to survive the day. But this is the subject of another conversation.
LEARNING ABILITY AND THE POWER OF CONSTANTLY ABSORBING NEW THINGS
Now that we understand a little more about our brain, it is easier to understand that biology has actually made us different. But it goes beyond that. Our brain, biologically speaking, has been the same for thousands of years. How did we manage to evolve from the cavemen period to the great technological advances we experience today? Thanks to our ability to organize processes and systematize our knowledge, to develop our own abilities and turn them into skills. And that growth has happened exponentially since more technology gives us more free time to think of more technologies, and so on, like a cycle. This way, we are increasingly dedicating ourselves to our ability to learn, systematically investigating our world, applying the technologies we have created, and forwarding that knowledge.
Our brain is much more than a cortex full of neurons: we do have this biological facility, but we also have the power to sculpt the neurons we receive. When we were born, we already had extra synapses. We are like a marble block that can turn into almost everything, but this alone is not really useful. Learning is what gives shape to this block. Over time, our brains keep the connections and neurons that matter and remove useless connections. Learning is the process of keeping connections and removing connections. And that’s how we sculpt our “marble block” and makes each of us unique individuals.
Throughout our lives, we learn things in an eternal system of trial and error. And our brain has a mechanism developed for this: when what we attempt works out, it rewards us with a sensation of pleasure. Then, the path we have taken to do something right is strengthened and becomes easier to do it again, neurologically speaking. The fascinating thing is that this system doesn’t happen only when we are babies learning about life. It happens along our whole life, all the time for everything we learn, from the simplest tasks to complex equations. To learn something, a person firstly needs a learning opportunity. These opportunities can come from other people (parents or friends who encourage us, for example) or they can be given to us, which happens only after we realize what we really want for ourselves and become open to knowing about the alternatives that life offers in order to keep learning. In our adult years, our ability to learn is in our hands. And it goes beyond learning exact or human sciences in a classroom. Anything can teach us. A good or bad experience is a huge learning opportunity. What we do with it will help us continue evolving, as people, as a species. Our advantage over other species on Earth is our ability to change our life for the better.