Social Brain Hypothesis
Why do humans have such large brains?
Over a span of nearly seven million years, the human brain has tripled in size, with most of the growth being seen in just the last two million years. Although many explanations for the growth of the human brain have been presented, one hypothesis that proves to be most accurate is the Social Brain Hypothesis as presented by Robin I.M. Dunbar. This hypothesis attempts to explain the cause in brain size evolution by attributing it to social relations and social changes happening in early human populations.
Homo habilis, the first of our genus Homo who appeared 1.9 million years ago, saw a modest change in brain size, including an expansion of a language-connected part of the frontal lobe called Broca's …show more content…
In primates, maintaining non-sexual pair bonds, “friendships”, involves serious cognitive work and emotions. While studying primates a linear relationship between time spent together and strength of relationship can be seen. The evidence to support these observations include the correlation between the numbers of alliances with the relative neocortex size. Human data on this topic is found to be similar to the observations of primates.
With the data given by Dunbar, the Social Brain Hypothesis proves to be the most accurate explanation as to why humans have such large brains. With the development of language alone there is a clear and evident change to the size and shape of the brain, specifically the frontal lobe. With the development of language, human relationship and other social aspects are thus stronger and more …show more content…
Williams was the first to offer the claim that menopause might be an adaptation. He explains that in some point during evolution, it became beneficial for females to stop “dividing their declining faculties between the care of extant offspring and the production of new ones” (p. 408). Essentially, this means that since a female’s dependent offspring would die if she did, older mothers in the population should stop producing new babies and focus on the offspring they already had. By doing this, the chance of death during childbirth would be eliminated and the chance of survival for the current offspring would be increased. In addition, the older females of the groups could offer knowledge and skills to other members of the group which, in turn, would enhance the overall fitness of the group.
In her article, “Human longevity: The grandmothering effect”, Kristen Hawkes explains the evolutionary advantage that post-menopausal females can have. Hawkes suggests that aging in all aspects of physiology would be slowed because the act of grandmothering would lead to greater reproductive success of the
Over a span of nearly seven million years, the human brain has tripled in size, with most of the growth being seen in just the last two million years. Although many explanations for the growth of the human brain have been presented, one hypothesis that proves to be most accurate is the Social Brain Hypothesis as presented by Robin I.M. Dunbar. This hypothesis attempts to explain the cause in brain size evolution by attributing it to social relations and social changes happening in early human populations.
Homo habilis, the first of our genus Homo who appeared 1.9 million years ago, saw a modest change in brain size, including an expansion of a language-connected part of the frontal lobe called Broca's …show more content…
In primates, maintaining non-sexual pair bonds, “friendships”, involves serious cognitive work and emotions. While studying primates a linear relationship between time spent together and strength of relationship can be seen. The evidence to support these observations include the correlation between the numbers of alliances with the relative neocortex size. Human data on this topic is found to be similar to the observations of primates.
With the data given by Dunbar, the Social Brain Hypothesis proves to be the most accurate explanation as to why humans have such large brains. With the development of language alone there is a clear and evident change to the size and shape of the brain, specifically the frontal lobe. With the development of language, human relationship and other social aspects are thus stronger and more …show more content…
Williams was the first to offer the claim that menopause might be an adaptation. He explains that in some point during evolution, it became beneficial for females to stop “dividing their declining faculties between the care of extant offspring and the production of new ones” (p. 408). Essentially, this means that since a female’s dependent offspring would die if she did, older mothers in the population should stop producing new babies and focus on the offspring they already had. By doing this, the chance of death during childbirth would be eliminated and the chance of survival for the current offspring would be increased. In addition, the older females of the groups could offer knowledge and skills to other members of the group which, in turn, would enhance the overall fitness of the group.
In her article, “Human longevity: The grandmothering effect”, Kristen Hawkes explains the evolutionary advantage that post-menopausal females can have. Hawkes suggests that aging in all aspects of physiology would be slowed because the act of grandmothering would lead to greater reproductive success of the