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Machavellian intelligence

allows an individual to serve his or her own intereby interacting with others either cooperativelyor manipulatively but without disturbing the oversocial cohesion of the group

think: corrupt politicians

positive feedback between social

complexity and brain size/intelligence

seen in carnivores and their ungulate prey Red Queen Effect!

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Primate group size

minimum group size

needed for defense against predators

maximum group size

ecological factors

social factors

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Larger groups

take longer to move from place to place

more conspicuous to predators

less food per individual when located

When a group becomes too large

conflicts arise over

food

dominance

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Thresholds where groups split

Benefit of group living must be weighed against co

Social Conflicts arise because of competition for

food

mates

Order is maintained by

Dominance Hierarchies

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High ranking individuals achieve

higher reproductive success

priority of access to resources

Complex Social Interactions

success also depends on

networks of alliances

coalitions

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Competition

Social Conflict

Predator Pressure

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Grooming as a tool to dissipate aggression and co

used to solicit altruistic interactions

for reconciliation after conflict

maintains friendships

cements alliances

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The role of deception

mislead others

by giving false information

false warning calls

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Social Primates must

be able to recognize individuals

keep track of social debts - yours and others

know relatedness between individuals

be able to consider how a situation would look

to another individual

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Intentionality

zero-order: a rock unaware of its own existence

first order: self-awareness

second order: self-awareness and realization thatothers are aware also

children acquire this between 3-4

Most adults can keep track of 5-6 orders

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1storder I think

2ndorder I think you think

3rdorder I think you think I think

Etc.

Self Awarenessvery hard to measure in animals

Mirror test

Humans, Apes, Dolphins, Elephants

Convergent Evolution

http://www.youtube.com/watch?v=W-pc_M2qI74

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The Human Brain

three main sections

primitive core

inherited from our reptilian ancestors

mid-section

sensory perception

integrating bodily functions

white matter

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outer layer

cerebral cortex

distinctive to mammals

grey matter

in mammals makes up 35% of the total brain

In primates

50% in prosimians

80% in humans

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Neocortex enlargement

driven by advantages ofprocessing and using

socially relevant

information

Multifactoral approach

To encephalisation

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Encephalisation and Runaway Sexual Selection

females preferred smarter males

offspring are smarter

sons are preferred mates

females inherit preference for smart males

positive feedback loop

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Sexual Selection and Brain Size: Display Hypothesis

males display intelligence via

art

music

making artifacts

telling stories

resulting in science, art & literature

female choice driving encephalisation in males??

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Genomic Imprinting and brain growth

traditionally thought that autosomes act same

doesnt matter if they come from mom or dad

Genomic Imprinting

when how a gene operates depends on its origin

paternally activecame from father

maternally activecame from mother

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Maternally active genes

see maternal siblings as related r = 1

act more altruistically towards maternal relatives

benefit via inclusive fitness

Paternally active genes

see maternal sibling as unrelated r = 0

act selfishly

attempt to forcibly extract more maternal

resources than the mother is willing to give

N t

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Neoteny

small genetic changes that effect timing of

development of features

skull of juvenile chimpanzee looks like human skull

suppression of genes that control skull maturation

results in the maintaining of juvenile skullproportions in adulthood

N l S l i d Th O i i f L

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Natural Selection and The Origin of Language

Steven Pinker 1994

inherited disorders

involving grammatical errors in speech

language areas of the brain Brocas area speech

Wernickes areas comprehension

language bears signs of being designed to serve a

specialized function

like the mammalian eye or bird wing

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children learn language naturally

and quickly

the human vocal tract is adapted

to speech

larynx low in throat

allows for expansion of types of sounds

auditory apparatus specialized for decoding speech

all human languages are grammatically complex