Task 5 Flashcards
Name the most important theories about how the human brain size came to be. (6)
- General Intelligence Hypothesis
- Adapted Intelligence Hypothesis
- Social Brain Hypothesis (Dunbar)
- Ballistic Hypothesis
- Expensive Tissue Hypothesis
- Cultural Intelligence Hypothesis
Explain the General Intelligence Hypothesis.
- Larger brains enable us to engage in more mentally challenging tasks.
Explain the Adapted Intelligence Hypothesis.
- Cognitive abilities evolve as a result of our environmental challenges.
Explain Dunbar’s Social Brain Hypothesis.
- Maintaining social relationships requires deliberate brain activity
- Individuals that maintain long-term relationships show larger brains (differs from species to species)
Explain why the Social Brain Hypothesis might be correlation instead of causation.
Increasing brain size takes up a lot of energy, so it only pays off over a long lifespan. Lifetime is increased by living in a group due to protection before predators.
Our relative brain size is similar to that of a mouse. What concept is reason for us to consider humans having a larger brain despite of this?
Allometry - Not every body part grows linearly in proportion with each other.
-> Brain size correlates with body weight in this way:
Brain Size = C*W^k | W=weight in g; k&C=constants that are species-dependent
If you take the logarithmic function of this, you get a line:
-> Expectation line
-> Humans lie above this expectation line
-> Actual brain size/expected brain size = Encephalization Quotient
-> Humans have an encephalization quotient of far over 1.
Why does a high Encephalization Quotient not mean high intelligence?
There might be Negative/Positive Encephalization/Somatization.
-> Chihuawas have a high EQ because of negative Somatization.
Explain the Ballistic Hypothesis
We need a large brain to estimate projectile trajectories, which was evolutionary beneficial.
-> Also supposed to have lead to handedness and lateralization in the brain.
Explain the Cultural Intelligence Hypothesis.
Social-cognitive skills are what differentiates humans from other animals.
- Experiment: Human children of 2.5 years had similar performance in different physical and cognitive areas as chimpanzees and orangutans, however they were much more adapt in social domain tasks.
How can hierarchies have an effect on the human mind?
- Dominance Hierarchies are difficult to keep track of and require mental effort
- if the hierarchy is steep and stable, this has a negative effect on the mental state of lower ranked individuals
- if it is unstable, the higher ranked individuals suffer more
Name six things, that make us human and explain where necessary.
- Meat Consumption
- expensive tissue hypothesis - Tool Use
- related to Adapted Intelligence Hypothesis and Meat Consumption - Brain Size
- Social Brain Hypothesis
- Related to learning and other tasks - Life History
- Humans have developed a lot since their emergence compared to other species.
- humans undergo a lot of physical and cognitive change after birth
- Slow structural and fast cognitive development
- Long Lifespan
- High cost of having offspring -> Multi-Generational engagement - Learning
- Learning many ways to kill prey
- Social learning
- Specialized jobs for each person as a result of cooperation
- makes it possible to populate various different terrains - Language
- Productive Language System
- Social Applications
- Gene FOXP2
When did the separation between humans and chimpanzees happen?
5-7mio years ago
What is the technical term for our ancestors, after the separation from great apes?
Hominins
What are the three main hypothesises of how the modern human developed?
- A spread of a modern species out of Africa, replacing Neanderthals etc. without interbreeding
- A product of interbreeding between modern humans and Neanderthals
- In reality, it’s just one big species with Neanderthals etc. being just regional variations.
Which of the models of how the modern human developed has the most evidence?
Out of Africa Model:
- There are no morphological features that are retained from European or Asian ancestors.
- Molecular phylogeny shows, that we stem from a sub-branch of the African tree.
- Neanderthal DNA is much more similar to each other than AMH DNA, which speaks against interbreeding.
