Culture and Human Nature

Is Culture unique to humans?

Culture refers to some kind of symbolic coding
- Having a set of signals, icons, and words that refers to something else that most members of that culture recognize
Humans are by no means the only species that have culture
- There are many examples of cultural learning in the animal kingdom
  - Chimps have been shown to use tools to extract termites from their mounds – they take a trig, peel the bark, and stick the twig into the termite mound
  - Killer whales have been found to speak different dialects to the point where researchers recognize a whale pod by the sounds they make – these dialects change over time, just as human culture does

Humans are not unique in being able to engage in cultural learning
Humans seem to be unique among other species in whom they choose to imitate
In a study, 4 year old children were more likely to imitate a prestigious model rather than the model that had been ignored by others
Humans have a prestige bias that makes them especially likely to imitate those who are viewed by others as more prestigious o This skill was likely selected for in the course of human evolution  Humans cultural learning skills rest on 2 key practices:
1. The ability to consider the perspective of others
2. The ability to communicate with language

A theory of mind means that people understand that others have minds that are different from their own, and that other people have perspectives and intentions that are different from their own o Is not evident in most other species o Has important consequences for cultural learning
Imitative learning: where the learner internalizes something of the model’s goals and behavioral strategies
Emulative learning: where the learning is focused on the environmental events that are involved – how the use of one object could potentially effet changes in the state of the environment o Key difference between the two***
- Emulative learning does not require imitating a model’s behavioral strategies
- Emulative learners are focusing on the events that happen around the model rather then what model intends to accomplish
- Emulative learners try to figure things out for themselves once they get an idea by observing others o Chimpanzees and other primates tend to solve problems using emulative vs. imitative learning
When children imitate a model, they imitate all of the model’s actions, including irrelevant ones
In contrast, chimps only copy the behaviors that are directly relevant to achieving the goal while ignoring the irrelevant ones
Emulative learning is often very effective but does not allow for cultural information to accumulate

Cultural ideas are most successfully transmitted through language
Humans differ from their nearest primate relatives in terms of their abilities to have theory of mind and to have an extensive language – both allow for humans to learn from each other in ways that other species cannot
Humans cultural learning is cumulative

Human cultural is cumulative meaning that after an initial idea is learned from others, it can then be modified and improved upon by other individuals
The cultural info then grows in complexity and utility over time
This is called the ratchet effect

o Cultural info can continue to accumulate without losing the earlier info

An example of cumulative cultural evolution would be the evolution of the hammer – from archaeological time (using a stick attached to a stone) to modern times (hammer in the shop)
Cultural idea such as democracy or money also represent the accumulation of idea and innovation spread out over human history

Encephalization quotient (EQ): the ratio of the brain weight of an animal to that predicted for a comparable animal of the same body size o Our brain is about 4-5 times larger than that of other mammals our size
Our brain consumes about 16% of all our basal metabolism
It constitutes only about 2% of our body weight

Humans have considerably less muscle mass than chimpanzees
Having less muscles mass allowed for a larger portion of our energy to be consumed by our brains
As we became a weaker ape, we were able to redirect some of that energy and become a smarter ape
The digestive tract is about 60% smaller in humans than what would be expected in a primate of our body weight
Smaller digestive tracts saves humans approx.. 10% of their daily energy expenditures
By cooking our food, we were able to evolve a much smaller digestive tract , which freed up much energy to be used by our brains
Cooking, a cultural invention, is thus partly responsible for our biological nature

What is the evolutionary advantage of a large brain?

First theory rests on the observation that primates eat a lot of fruit – perhaps the selection for big brains in primates was driven by the need for cognitive abilities that would help them keep a mental map of the short-lived and patchily distributed fruit that was around them o Primate who had better skills at remembering where the fruit was would have been more likely to eat well and to have surviving offspring
Second theory regarding the relevance of the diet of primates involves how many primate species rely on food sources that require a fair bit of ingenuity to access them – primates who were smart enough o figure out how to open the nuts and get themselves a nutritious meal would have had more surviving offspring
Third theory has to do with the complexity of primates and their social worlds – perhaps it was the great cognitive demands inherent in social living that led to the evolution of large primate brain o This theory has become known as the social brain hypothesis o Those primates who were most successful in social relationships would have been more likely to attract mates, secure resources, and protect themselves and their offspring from dangers

o Best supported theory for why primates got their large brains

To measure intelligence, researchers calculate the ratio of the volume of the neocortex to the volume of the rest of the brain o Known as the neocortex ratio
Primates tend to be highly social animals, and this requires considerable cognitive skills
Humans appear to have evolved the cognitive capacities to function best in groups of around 150 people
The primary way that humans differ from other apes is in terms of their ability to learn from others
The ability to engage in cultural learning itself was a selective force that has shaped human evolution since we last shared common ancestors with other primates
Culture, therefore, was central ”ingredient” to human evolution – we evolved to depend on cultural learning