Your neocortex controls how
The neocortex, also known as the neopallium, is a section of the cerebral cortex in the brain. Simply put, the larger the relative volume of the neocortex region of the brain, the higher the number of people a certain individual may socialize safely with within a group, without any artificial system of laws or regulations.
In the further matured minds of certain species such as Homo sapiens (modern humans) and various primates, the development of the neocortex has played a crucial role in the evolutionary and social aspects of life. In order to better understand the impact of the neocortex, much research has been conducted on numerous clans, or better yet, societies, of primates and modern hunter-gatherer groups. After Dunbar examined numerous troops of baboons, he gleaned information that led him to establish that the constraint of the neocortex influences the number of relationships that the animal can maintain.
When analyzed through an evolutionary lens, scientists were able to infer that the size of the specie's neocortex may even be controlled by the necessary group size that the habitat requires. With this said, after analyzing dissected monkey brains and examining neocortex size, scientists were able to predict the size of that specific monkey's tribe. This direct relationship between ecological factors and neocortex size is also proven when primate groups reach their maximum size they seem to become unstable and experience "social disintegration".
The best fit reduced major axis regression equation between neocortex ratio and mean group size for a sample of 36 primate genera was found to be:
When this equation was used for Homo sapiens, it yielded a group size of 147.8, significantly close to the theorized 150.
He then compared this number to the group sizes of humans around 252,000 years ago (Pleistocene epoch), assuming that the evolution of human brain size had finished at around that time period to keep the size of the neocortex, a decisive variable, constant. He picked the earliest date possible as any advancement in technology or communication techniques that may help to break social barriers may distort Dunbar’s number with another variable. It turns out that the majority of the approximations he made of the group sizes during this time period were around 150 members, giving him solid evidence to support his number of 150.
Some people may, however, question the validity of the number in today’s world, where communication has come to the point where very few close social relations are needed to survive and make accomplishments. So how is it used?