In this blog post, we will explain the origin of the myth that we only use 10% of our brain and whether it is true based on scientific facts in an easy and interesting way.
“Most humans use only 5 to 6 percent of their brains. But I use 7 percent.” This is said to be a quote from the famous scientist Albert Einstein, but in fact, he never said this during his lifetime. Nevertheless, it has become a favorite quote of many people and has influenced as many people as Albert Einstein’s theory of relativity. The story that people use only 10% of their brains in their lifetime has spread like an established fact. So, do humans really use only 10% of their brains in their lifetime?
To cut a long story short, this gossip is unfounded. Even scholars who have studied the metabolic activity of brain cells unanimously say that there are no non-functional areas in the brain. Basically, almost all of the brain’s nerve cells are used. The human brain has 100 billion cells, each of which is connected to at least 10,000 other cells, working busily to fulfill its role. However, not all areas of the brain are activated at the same time. Barry Gordon, a neurologist at Johns Hopkins School of Medicine, said, “Humans actually use every part of the brain, and most areas of the brain are almost always active. However, at certain moments in a person’s life, for example, when we are simply resting, we may only be using about 10% of our brain,” he said. In other words, humans use their entire brain throughout their lives, but not the entire brain at every moment, and certain areas of the brain are activated according to the needs of the moment.
The imaging data of the brain also provide strong evidence that humans use the entire brain. Studies using other imaging devices, such as PET (positron emission tomography), CAT, and fMRI, have shown that there are no dormant areas in the brain. Even when looking at individual neurons or cells in the brain, it is said that there are no inactive ones. “These imaging data show that humans use 100% of their brains in a single day,” said John Henry, a neurologist at Mayo Clinic (Rochester, Minn.) who presented the findings using imaging devices. Even while a person is sleeping, the frontal lobe, which is responsible for higher-order thinking and self-awareness, and the somatosensory system, which allows humans to perceive their surroundings, are active.
In fact, the brain’s activity does not decrease much while sleeping. While dreaming, the brain plays an important role in processing sensory information and organizing memories. During this process, various parts of the brain are activated, and in particular, the areas where visual experiences and emotional processing take place are active. Therefore, the fact that humans use a significant portion of their brains even while sleeping is evidence that refutes the myth that the brain is only 10% used.
The myth that humans use only 10% of their brains can also be refuted from the following developmental perspective. When the nervous system is first created, numerous synapses, which are the junction sites that connect nerve cells to each other, are formed in the brain. However, a large number of synapses are eliminated after the baby is born. The synapses that are eliminated at this time are those that are not used due to the lack of constant stimulation. In fact, the human brain is designed to eliminate synapses if they are not continuously stimulated appropriately. The same developmental theory that explains how unused organs are eliminated and disappear applies to the nervous system. This was proven by experiments conducted by Nobel Prize winners David H. Hubel and Torsten N. Wiesel. The experiments proved that if visual information (appropriate stimuli) is blocked during the early stages of the nervous system’s development, the visual ability itself will eventually be lost forever. Therefore, from a developmental perspective, if 90% of the brain is not being used, the nerve synapses in that part should have disappeared. However, the fact that synapses have been found to be distributed throughout the entire brain means that the myth that humans use only 10% of their brain is not true.
However, it is true that the brain is not yet using 100% of its capacity. According to theoretical neurologist Dr. Dmitri Chklovskii, the number of synapses in the brain is less than 30% of the maximum capacity. In theory, the number of available synapses in the brain still has about 70% of the capacity to be used. In other words, almost all brain cells are active, but the connections between them are not yet saturated. This leaves room for human learning ability and adaptability, meaning that humans can still expand the function of their brains through new experiences and learning. As such, the brain has the potential to constantly develop through experience and learning.
The myth that humans use only 10% of their brains comes from the 19th-century psychologist William James, who claimed that “ordinary people use 10% of their brains, while geniuses use 15-20%.” This was miscommunicated in the process of explaining this. Since then, self-development experts have often cited this theory to tell their audiences that human potential is limitless. This has led to the claim being widely believed as if it were true. However, humans have the ability to use the entire brain and, furthermore, to use various areas of the brain in the right places.
In fact, when discussing the usage and potential of the brain, it is not simply the quantity that is important, but the quality. In other words, it is more important which part of the brain is activated and how efficiently. For example, when performing complex mathematical calculations or learning a new language, certain brain regions are particularly active. At this time, certain circuits in the brain are used very intensively, while other parts may be relatively less active. The brain’s areas that are activated differently depending on the situation are what make humans more focused and creative in certain activities.
Ultimately, the fact that humans use their entire brain is not a factor that limits human potential, but a driving force that has enabled the development of humanity to date and a stepping stone that will play a pivotal role in future leaps forward. Furthermore, the human brain has the ability to continue to change and grow, and this possibility suggests infinite possibilities for how much more potential we can unlock in the future. Scientists are still in the process of unraveling the mysteries of the brain, and the more we learn about it, the more possibilities it will open up.
