Origins Of Social Influence Flashcards
History of humans
- humans are part of the order of primates
- our closest living relatives are other apes, chimpanzee and bonobos
- primates invest heavily in small numbers of offspring with long periods of care after birth, delayed sexual maturity and relatively long life- spans (this has an effect on our complex social structures)
Homo sapiens
- they migrated out of Southern Africa 200,000-300,000 years ago
- from the earliest days of humans there were atleast 3 different species of humans co-existing and presumably interacting
- around 50 Kya, Homo sapiens displaced the other early human species
- Homo sapiens migrated across the globe, there was an explosion of technological developments “the great leap”
Why have we evolved such large,costly brains?
Dunbar considers two very general classes of explanation
- ecological pressure
- social selection
Ecological pressures
The idea that large brains are the result of national selection pressures based on the physical environment: such as diet, hunting and territory
- Dunbar uses a measure of brain size called neocortical volume, relevant way to measure brain size
Dunbar and correlation between brain size and body size
Dunbar showed that across many primate species, differences in the species’ relative brain sizes are uncorrelated with a variety of ecological measures
- like the dependence of hard-to-gather fruit in the diet, and territory size
(The idea that brain size is a result of ecological pressures doesn’t stand up well)
Social selection
- when relative brain size of different species are plotted against ‘group size’- that is, the size of typical social groups, colonies, and herds - a clear correlation is found
- supports the finding that increasing brain size facilitates living in larger groups
Social selection hypothesis
Human brain size has evolved to promote survival and reproduction within large human groups
- in turn, large human brains seem to allow group sizes to increase yet remain effective
Correlation between neocortex and group size
Positive strong correlation
Average group size for a human around 150
What does Dunbar note about 150 as an average group size for a human
He notes 150 seems to be an upper limit for human groups that are maintained by peer-to-peer interaction, rather than by some hierarchical structure or bureaucracy
How does a larger brain benefit living in a larger group?
Theory of mind
Theory of mind
- theory of mind allows influence
- individuals best equipped to understand the others in the group would therefore have the most success within the group
- this line of thought suggests that the ability to create influence is absolutely central to the evolution of the human brain
Human ‘cumulative culture’
- many animals are capable of learning from each other, within limits
- human social learning is unique in the degree to which technology and innovations achieved in the past are maintained and built upon, to allow new innovations and development
Human cumulative culture
As individuals we are limited in how much we can innovate and in how much we can exert control over our environment, our cultural inheritance from previous generations
How has society not always been a ‘cumulative culture’
For a very long time, the classic “hand axe” stone tool was the epitome of technological development
Limited development in tools, then all of a sudden there was a rapid development “the great leap”
What was the basis of ‘the great leap”
It’s unknown.
There were no change in brain size
May have been triggered by relatively sudden developments in language use
