PSYC 2410 Chapter 2: chapter 02 notes
27 Jun 2018
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Thinking about the biology of behaviour - from dichotomies to interactions:
The origins of dichotomous thinking
oWe tend to ignore the subtleties, inconsistencies, and complexities of our existence and
to think in terms of simple, mutually exclusive dichotomies
oThe tendency to think about behaviour in terms of dichotomies is illustrated by two
kinds of questions commonly asked about behaviour: is it physiological, or is it
psychological? Is it inherited, or is it learned?
oSome Renaissance scholars were not content to follow the dictates of the Church;
instead, they started to study things directly by observing them - and so it was that modern
science was born
oFrench philosopher, René Descartes advocated a philosophy that gave one part of the
universe to science and the other part to the church
He argued that the universe is composed of two elements:
physical matter, which behaves according to the laws of nature and is
thus a suitable object of scientific investigation
The human mind, which lacks physical substance, controls human
behaviour, obeys no natural laws, and is thus the appropriate purview of the
Church
oDescartes philosophy became known as Cartesian dualism and was sanctioned by the
Roman Church and the idea that the human brain and the mind are separate entities
became even more widely accepted
oPeople nowadays understand that human behaviour had a physiological basis, but many
still cling to the dualistic assumption that there is a category of human activity that
somehow transcends the human brain
oFor centuries to come, scholars have debated whether humans and other animals
inherit their behavioural capacities or acquire them through learning - this debate is known
as the nature-nurture issue
oEuropean ethology, in contrast to North American experimental psychology, focused on
the study of instinctive behaviours, and it emphasized the role of nature, or inherited
factors, in behavioural development
Because instinctive behaviours are not learned, early ethologists assumed they
were entirely inherited - they were incorrect and so were the early experimental
psychologist who were committed to the nurture side
Problems with thinking about the biology of behaviour in terms of traditional dichotomies
oThere are two lines of evidence against physiological-or-psychological thinking
The first line is composed of the many demonstrations that even the most
complex psychological changes can be produced by damage to, or stimulation of,
parts of the brain
The second line is composed of demonstrations that some nonhuman species,
particularly primate species, possess abilities that were once assumed to be purely
psychological and thus purely human
oThe first case is Oliver Sack's account of "the man who fell out of bed" - point to take
from this is that although the changes in self-awareness displayed by the patient were very
complex, they were clearly the result of brain damage
oThe second case describes G.G. Gallup's research on self-awareness in chimpanzees -
point of this case is that nonhumans, which are assumed to have no mind, are capable of
considerable psychological complexity (self-awareness)
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oFactors other than genetics and learning were shown to influence behavioural
development; factors such as the fetal environment, nutrition, stress and sensory
stimulation all proved to be influential
This changed the nature-to-nurture dichotomy from "genetic factors or
learning" to "genetic factors or experience"
oIt was argued convincingly that behaviour always develops under the combined control
of both nature and nurture, not under the control of one or the other
Human evolution:
Darwin's theory of evolution
oDarwin was not the first to suggest that species evolve from pre-existing species, but he
was the first to amass a large body of supporting evidence and the first to suggest how
evolution works
oHe presented three kinds of evidence to support his assertion that species evolve:
He documented the evolution of fossil records through progressively more
recent geological layers
He described striking structural similarities among living species, which
suggested that they had evolved from common ancestors
He pointed to the major chances that had been brought about in domestic
plants and animals by programs of selective breeding
oThe most convincing evidence of evolution comes from direct observations of rapid
evolution in progress
oHe argued that evolution occurs through natural selection
Evolution and behaviour
oThe males of many species establish a stable hierarchy of social dominance through
combative encounters with other males
oSocial dominance is an important factor in evolution because in some species, dominant
males copulate more than nondominant males and thus are more effective in passing on
their characteristics to future generations
oIts also an important factor in evolution in that in some species, dominant females are
more likely to produce more and healthier offspring
oAn intricate series of courtship displays precede copulation in many species - courtship
displays are thought to promote the evolution of new species
oThe reproductive barrier may be geographic or behavioural
Course of human evolution
oBy studying fossil records and comparing current species, we are able to look back in
time and piece together the evolutionary history of our species
oPrimates of the tribe that includes humans are the hominini - this tribe is composed of
at least 6 genera (genus)
oHomo is thought to be composed of at least 8 species - seven of which are now extinct.
The only surviving homo species are homo sapiens
Thinking about human evolution
oEvolution does not proceed in a single line
oWe humans have little reason to claim evolutionary supremacy - we are the last
surviving species of a family that has existed for only a blip of evolutionary time
oEvolution does not always proceed slowly and gradually - rapid evolutionary changes
can be triggered by sudden changes in the environment or by adaptive genetic mutations
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Thinking about the biology of behaviour - from dichotomies to interactions: The origins of dichotomous thinking: we tend to ignore the subtleties, inconsistencies, and complexities of our existence and to think in terms of simple, mutually exclusive dichotomies o. Is it inherited, or is it learned? o. Some renaissance scholars were not content to follow the dictates of the church; instead, they started to study things directly by observing them - and so it was that modern science was born o. French philosopher, ren descartes advocated a philosophy that gave one part of the universe to science and the other part to the church. He argued that the universe is composed of two elements: physical matter, which behaves according to the laws of nature and is thus a suitable object of scientific investigation. The human mind, which lacks physical substance, controls human behaviour, obeys no natural laws, and is thus the appropriate purview of the.
