The human brain is exceptionally unique , it has very complex characteristics in relation to the rest of the animal species, including our phylogenetic cousins, the primates.

The capacities of human beings are extremely specific to our species: we can think in very complex terms, be creative and create technological devices that make our lives easier, and furthermore, we are the only species with the capacity to be able to study other animals and their behaviour.

Why are we so special? The human brain…

For years the scientific literature postulated that cognitive capacity was proportional to the size of the brains . This is not entirely correct, since two mammals with similar-sized brains, such as a cow and a chimpanzee, should have equally complex behaviors, which is not the case. And what is even worse: Our brain is not the biggest one there is. Anyway, our brain, despite not being the biggest, is the best in terms of cognitive ability .

It seems that the special quality of our great cognitive capacity does not come from the size of the brain in terms of its mass, but from the amount of neurons it contains . And this is where we find a study carried out by Suzana Herculano-Houzel, a Brazilian neuroscientist, who was entrusted with the task of determining the number of neurons in the human brain.

Before their research, the vast majority of neuroscientists claimed that the human brain possessed 100 billion neurons. The truth is that this figure was never determined in any study and was a norm for years within the scientific literature.

This is how Suzana Herculano-Houzel, through a method she designed, manages to determine the final figure for the number of neurons in the human brain: 86 billion neurons in total, of which 16 billion are in the cerebral cortex (cortex involved in complex cognitive processes). And by applying the same method to the brains of different mammals and comparing them, he discovered that the human brain, although not the largest in terms of mass, is quantitatively the largest in the number of neurons it possesses, even with primates, with whom we share many of our genetic load (97%). And this would be the specific reason for our cognitive abilities.

Why did human beings evolve to this amazing complexity?

From this, other questions arise: How did we come to evolve into this amazing number of neurons? And particularly, if primates are bigger than us, why don’t they have a bigger brain with more neurons?

To understand the response to these situations, one must compare the body size and brain size of primates. He found that because neurons are so expensive, body size and number of neurons compensate for each other. So a primate that eats 8 hours a day can have a maximum of 53 billion neurons, but its body couldn’t be bigger than 25 kg, so to weigh much more than that, it must give in on the number of neurons.

From determining the amount of neurons that the human brain has, it is understood that it needs an enormous amount of energy to maintain it. The human brain consumes 25% of the energy even though it only represents 2% of the body mass . To be able to maintain a brain with such an amount of neurons, with an average weight of 70 kg, we should dedicate more than 9 hours a day, which becomes impossible.

Humans cook food

So if the human brain consumes so much energy and we cannot spend every waking hour on our food, then the only alternative is to somehow get more energy from the same food. Thus, this coincides with the incorporation of food cooking by our ancestors one and a half million years ago .

Cooking is using fire to predigest food outside the body. Cooked foods are softer, so they are easier to chew and to mash in the mouth, which means they can be better digested in the stomach and allow greater amounts of energy to be absorbed in much less time. In this way, we obtain a great amount of energy for the functioning of all our neurons in much less time , which allows us to dedicate ourselves to other things beyond feeding ourselves and thus stimulate our cognitive capacity achieved with a brain of such magnitude.

So what is the advantage we have as human beings? What do we have that no other animal has?

The answer is that we have the brain with the largest number of neurons in the cerebral cortex, which explains our complex and extraordinary cognitive abilities to all of nature.

What do we do, and what does no animal do, to allow us to reach such a quantity of neurons in the cerebral cortex?

In two words: we cook. No other animal cooks its food to digest it, only humans do. And this is what allows us to become human as we are.

From this conception, we must realize the importance of food, how food influences the maintenance of our cognitive skills and the extent to which we achieve behaviors of enormous complexity.

So you know: the next time your mother cooks something you don’t like or you hear that someone is going to study gastronomy, congratulate them, because with their contributions they continue to make our cognitive skills just as complex.