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Unformatted text preview: Evolutionary Cognitive Psychology: The Social Brain Evolutionary Psychology "In the distant future . . . psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation." Charles Darwin, 1859 Evolutionary Psychology Nothing in biology makes sense except in the light of evolution. Theodosius Dobzhansky Nothing in psychology makes sense except in the light of evolution. Every evolutionary psychologist Hominid Evolution Increases in brain size during evolution ardipithecus brain size: 300 ccs Australopithecus brain size: 310-530 ccs homo habilis brain size: 580-752 ccs homo erectus brain size: 775-1225 ccs Neandertal brain size: 1200-1450 ccs modern human brain size: 1350 ccs Human Evolution: Pathways Species Similarity approximately 6 percent of human and chimp genes are unique to each species; 1.5 percent nucleotidebynucleotide difference between humans and chimps Similar Brain Structures Chimpanzee Tool Use & Teaching Memory Abilities Hunting with Tools Researchers in Senegal recently spotted wild chimpanzees biting the tips of sticks, which they then used like spears to jab small primates called bush babies. Physical Differences Between Primates Developmental Stages
20 15 Age in Years 10 Adulthood Adolescence Juvenile Childhood Infancy 5 0
Pan troglodyte A. afarensis H. habilis H. erectus H. erectus H. sapiens (early) (late) Humans as a Species: Locke & Bogin (2006) 1. slow and steady rate of body growth. 2. large, fastgrowing brain 3. higher resting metabolic rate than any other mammalian species 4. immature dentition 5. dependence on older people for care and feeding 6. motor and cognitive advances. Why Have a Large Brain? The adult human brain typically weighs about 3 lb. The mature human brain consumes some 20 25% of the energy used by the body, while the developing brain of an infant consumes around 60%. Why Have a Large Brain? Perez Barberia & Gordon (2005) The data set analyzed gathered from a total of 422 specimens of 86 species of ungulates Species with longer gestation length and those that were gregarious had larger brains relative to body size than those species with shorter gestation length and non gregarious species. The Ultimate Question Social brain hypothesis Gregarious species have evolved larger brains than nongregarious species, because species that live in groups are exposed to continuous social interactions that require demanding and complex information processing and fast responses to maintain group cohesion Social Brain Hypothesis The Social Brain: Cultural Learning ...
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This note was uploaded on 04/18/2008 for the course EXP 3505 taught by Professor Grotuss during the Spring '08 term at FAU.
- Spring '08