Does the happiness depend on the size of the brain? It is a big question now. The human species has risen, for better or for worse, as the dominant animal on our planet. Its scientific and technological development has led to unprecedented changes in the natural history of the earth.
Human beings have built great civilizations, built complex societies and forged common symbols for communication between individuals.
It has even conquered territories beyond the physical limits imposed by the horizon (the moon, other continents, etc.). This progress has been frenetic, something that can only be explained by a differential nuance: our intelligence.
Where does intelligence come from? Is it from the size of the brain?
To better understand this intelligence, we must delve into its organic support: the brain. This represents 2% of the total body mass in humans. The 76% of the fabric surface corresponding to the most recent point region and its evolution:
In this extensive territory of the brain parenchyma inhabit the higher order cognitive functions that have allowed our unprecedented development.
On the other hand, one of the most used indicators to infer the intelligence of every living being is the relative weight of its brain with respect to the total body mass .
In this sense, the human brain has the highest rate of all primates . This would explain the achievement of evolutionary milestones necessary for the advancement of the species.
Current evidence suggests that there is a direct relationship between the size of the neocortex and the ability of an animal to build large communities . Therefore, this region could be responsible for the cognitive revolution that our species went through thousands of years ago.
In recent times, a particular neurotransmitter in our nervous system is being studied to understand why we are the way.
Functions and peculiarities of serotonin
Serotonin is one of the main neurotransmitters in the human brain. It has multiple functions that help regulate your balance. Although this is known in the popular heritage as the “hormone of happiness”, the truth is that it is not a hormone nor is it limited exclusively to stimulating the mood.
In fact, even this last relationship is currently in question , as various studies question the classic serotonergic hypothesis to understand psychological disorders such as major depression.
Serotonin plays a key role in regulating physiological functions necessary for survival; like hunger , sleep , pain, and sexual response .
Its contribution to learning and memory processes is also known . In other words, the acquisition of knowledge and its evocation for further processing through the unfathomable paths of reason.
On the other hand, its deficit has been consistently associated with self-directed and hetero-directed aggressive responses (from suicide to interpersonal violence).
Serotonin, beyond the human the size of the brain
There are also cells sensitive to serotonin in other regions of the body distant from the brain, such as the gastrointestinal tract (enteric nervous system). From its contribution, serotonin facilitates the homeostasis of the body in a broad sense.
In fact, the possibility that intestinal neural circuits could serve as an explanatory element to understand the relationship between the microbiota and certain mental disorders (gut-brain axis) is not ruled out .
Finally, there is prior evidence that serotonin also contributes to the proliferation and location of neurons in immature brains.
Regarding this, it has been described that an excess of it can negatively interfere with both parameters with respect to cortical neurons. It is precisely on this issue that, in recent months, the horizons of our knowledge have broadened.
Serotonin and human the size of the brain
There are many explanatory hypotheses that, for decades, have tried to elucidate why our brain differs from that of other living beings.
In this sense, various theories have arisen: from the contribution of fire to cooking food to genetic mutations of difficult parentage. Along these lines, it has also recently been suggested that serotonin could help solve this traditional unknown.
We have already commented on the role of serotonin during the gestation process in brain development, especially in the proliferation and location of neurons (migration).
To this fact should be added the latest finding by a German research team , which has described how the production of serotonin in the placenta would interact with the HTR2A receptor exclusively in humans, stimulating the production of stem cells.
This phenomenon would result in a comparable and extraordinary production of cortical neurons, and thus in an increase in cortical volume.
However, and despite being an interesting finding with multiple therapeutic applications, it may be simplistic to affirm that the “neurotransmitter of happiness” increases intelligence.
First, because serotonin is involved in many other functions other than mood. Second, because the cerebral bases of intelligence cannot be reduced to the generic size of the neocortical surface, but rather its functioning and its distribution are fundamental.