Psyc 385 Chapter 3 Summary

Chapter 2
Evolution, Genetics, and Experience



Thinking about the Biology of Behavior


 Origins of Dichotomous Thinking
o Cartesian dualism – the idea that human brain and mind are separate entities
 Universe is comprised of physiological and psychological
o Ethology – study of animal behavior in the wild
 Instinctive behavior – occur in all like members of species without being
learned
 Emphasizes the role of nature (inherited factors)
 Problems w/ Thinking about Behavior in Terms of Dichotomies
o Evidence against physiological-psychological debate
 Complex psychological changes can be produced by damage or
stimulation to the brain
 Ex: Asomatognoisia – deficiency in the awareness of parts of one’s
own body
o Left side of body, damage to right parietal lobe
o Changes in self-awareness are complex, but result of
damage
 Nonhuman species possess abilities that are assumed psychological and
purely human
 Ex: chimpanzees are self-aware and are capable of high
psychological complexity
o Nature-or-nurture
 Not just one or the other, but a combination of both
 Can’t ask “how much comes from either”, it comes from both
o Biology of Behavior
 All behavior is a product of three interactions
 Organisms genetic endowment, which is product of evolution
 Its experience
 Its perception of current situation


Human Evolution


 Darwin
o Evolve – undergo gradual orderly change from preexisting species
o Natural selection – leads to evolution of species that are better adapted for
survival
 Evolution and Behavior
o Social Dominance

, Chapter 2
Evolution, Genetics, and Experience
 Males establish hierarchy of social dominance
 Let them know who’s boss, dominant male wins encounters
 Why important?
 Dominant males copulate more
 Dominant females produce more and healthier offspring
o Courtship Display
 Animals court through signals, must be reciprocated
 Species – group of organisms reproductively isolated from other
organisms
 Members can produce fertile offspring by only mating with other
species members
 New species branch from existing ones when a reproductive barrier
approaches, fertilization becomes impossible
 Barrier might be behavioral
 Only suitable exchange of displays between couple leads to reproductions
 Course of Human Evolution
o Vertebrates
 Chordates – animals with dorsal nerve chords
 Chordates evolve to have spinal bones to protect nerve chords
 Spinal bones = vertebrae, animals that possess = vertebrates
 7 classes  3 classes of fish, amphibians, reptiles, birds, mammals
o Amphibians
 Advantages
 Terrestrial food sources
 Escape pools to fresh water
 Fins and gills to legs and lungs
 Larval state must live in water
o Reptiles
 Evolved from amphibians
 Lay eggs
 Doesn’t need water at all
o Mammals
 Females feed young with secretion from mammary glands
 Stopped laying eggs, nurture young in watery bodies
 Primates = humans
 20 different orders of mammals
 16 families of primates
o Humankind
 Hominini – primates of the tribes of human
 Composed to six genera
o Australopithecus, Paranthropus, Sahelanthropus, Orrorin,
Pan, Homo