Why do we have such big brains?


Humans have lived with a variety of hominids that have surpassed, killed, or bred with them, and although we hear constantly news about human violence, we are extremely sociable beings, and although we live in cities with millions of people, we live together relatively serenely, and all this is due to an extremely large, complex and developed “social” brain.

Even for the neurobiologist Steven Rose, it is an extremely complex mystery how our brain works, we would have to know everything about the 86 billion neurons, their 100 trillion connections, and all their functioning up to the more than 1000 proteins that exist in every connection, and yet we would know practically nothing, for it would be necessary to know how these connections would have evolved during the person’s life and even the social context in which they arose, and it would take centuries to understand the basic neurological connectivity.

Although many people think that our brain functions as a superpowerful computer, the reality is not quite that, and although the senses, learning ability and reflexes are born with us, information, rules and algorithms and everything else, are not born with us, and these are crucial to the “intelligence” of computers.

In addition, computers have the ability to keep information for long periods of time, even without any type of power supply, our brains are capable of creating information or false memories, and only keeps information while we are alive.

Of course, there are several advantages in terms of a large brain, because it allows us to cohabit in large-scale groups, thus also diversifying food production and sharing, and also allows us to specialize in specific areas so that we are always the best in the fields and functions we perform, whether they are more or less complex.

Since humans do not have weapons in their bodies, the ability to use tools and to unite in large groups becomes crucial to their survival. Living in large groups implies a high cognitive capacity, and as soon as we leave that group, we lose access to everything from food to the security provided by it.

Anthropologist Robin Dunblar of Oxford University believes that our brain has the dimensions it presents today because of the need to store all the data of all the social reactions we have and it takes a great cognitive ability to subsist in large social groups.

The human brain is extremely flexible and has the capacity to organize itself according to the environment and society in which the individual develops, so with each birth, the brain of this new being adapts itself to the conditions that surround it, and this let us understand why in general the previous generations don’t understand the following generations, due to the different way in which their brains were developed.