As a child, we have been taught that humans are different from animals. But what makes us different from animals or even other primates?
A recent study conducted by an international research team tried to answer it.
In a study published in PNAS, Monday (22/1/2018), the researchers revealed that this difference exists in dopamine compounds in the brain.
For information, dopamine compounds are found in humans and other animals such as primates. Even so, they prove that humans have more dopamine that makes humans more friendly and less aggressive than other living things.
These dopamine compounds also help humans to help each other, limit sexual relations, and reduce aggression between groups.
"Humans have tremendous demographic success compared to their closest relatives in social, linguistic, empathy, and altruism," said Owen Lovejoy of Kent State University in Ohio, quoted by Eurekalert on Saturday (27/1). / 2018).
Lovejoy continues, researchers now have a duty to be able to explain how dopamine can change human social behavior and distinguish it from other primates.
In response to the challenge, the research team collected 38 samples of human brain tissue and some primates such as fringed capuchin monkeys, pig-tailed apes, olive babies, gorillas, and chimpanzees all died of natural causes.
Researchers focused on the part of the brain's striatum that functions to sort messages for muscle movement, learning, and social behavior.
They observed the chemical compounds in brain tissue that respond to different connective nerve cells to see the amount of dopamine, serotonin, and neuropeptide Y. All of the neural connecting cells are related to social behavior and cooperation.
As a result, humans and apes have more serotonin and Y neuropeptides than others. Dopamine in humans shows more numbers, while the amount of human acetylcholine associated with fewer territorial behaviors than other creatures.
This means the findings are consistent with previous research that the expression of TH gene in humans is higher than that of chimps. The TH gene plays a role in the production of dopamine.
The process of human evolution in the brain is difficult to ascertain, but this kind of neurochemical analysis can help us get a clearer idea. Anthropologists also think about some major differences to explain how we can move to upright walking, developing tools, and shaping advanced civilizations.
Different chemical levels in the striatum also affect the personality and social behaviors of chimpanzees and humans when their brains are the same size, about 7-9 million years ago.
"When viewed from the perspective of human fossil records, the difference in chemical compounds in the brain nerve is likely to lead to the roots of human origins or hominids responsible for their early failures," said Mary Ann Raghanti, of Kent State who is also the research coordinator.