Causes of Abnormal Behaviour

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Transcript Causes of Abnormal Behaviour

Chapter 2
Causes of Abnormal Behaviour:
A Systems Approach
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Thinking About Abnormal Behaviour
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What causes it?
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How should we study it?
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paradigms vs. systems theory
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Paradigms
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four traditional paradigms:
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biological
psychodynamic
cognitive behavioural
humanistic
assumptions inflexible & sometimes too
narrow
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Systems Theory
integrative approach (biopsychosocial)
 holism vs. reductionism
 multifactorial causes
 can not fully explain causes of most
abnormal behaviour
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Case Study: Meghan’s Hardships
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what caused Meghan to attempt suicide?
issues to consider:
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heredity
inter-uterine problems
early physical abuse and neglect
rejection from peers
failure at school
difficult relationship with her adoptive mother
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History of the Paradigms:
Pre-20th Century
 witchcraft
 development
of the scientific
method
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History of the Paradigms:
Biological
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cure of “general paresis”
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different from other forms of lunacy
linked to the STD syphilis
spirochete responsible for syphilis
discovered
penicillin used to treat syphilis
incidence of general paresis virtually
eliminated
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History of the Paradigms:
Psychodynamic
Freud’s (1856-1939) psychoanalytic
theory
 abnormal behaviour the result of
unconscious mental events
 mind consists of id, ego, and
superego
 used ideas to treat hysteria
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History of the Paradigms:
Cognitive Behavioural
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more concerned with treatment than etiology
initially, focus on observable behaviour rather than
“mind”
Ivan Pavlov (1849-1936) → classical conditioning
B.F. Skinner (1904-1990) → operant conditioning
John B. Watson (1878-1958)→ behaviourism
cognition increasingly viewed as an important
process in learning
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History of the Paradigms:
Humanistic
human nature is inherently good
abnormal behaviour is the result of
society not the individual
what is the meaning of life?
free will vs. determinism
more of a philosophy than psychology
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Systems Theory Revisited
 Diathesis-stress
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disorders typically have several risk factors
equifinality
multifinality
reciprocal causality
 Developmental
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model
psychopathology
utilizes developmental norms
allows for prognosis
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Development of Psychopathology
Biological Factors
Psychological Factors
Social Factors
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Biological Factors:
Neurons & Neurotransmitters
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Neurons
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smallest anatomic unit within the nervous system
dendrites →soma →axon →terminals→ synapse
Neurotransmitters
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released into the synapse by axon terminals
trigger receptors on dendrites
over or undersupply linked to mental disorder
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Biological Factors:
Neural Networks
very complicated in the human brain
change as a function of experience
Donald Hebb (1904-1985)
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Biological Factors:
Brain Structures
hindbrain, midbrain, forebrain
limbic system
hypothalamus and thalamus
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Biological Factors:
Cerebral Hemispheres
lateralization of function
 coordination of function
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corpus callosum
four ventricles
 cerebral cortex
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frontal lobe
parietal lobe
temporal lobe
occipital lobe
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Biological Factors:
Endocrine System
release hormones into the
bloodstream
regulates aspects of normal
development
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Biological Factors:
Autonomic Nervous System (ANS)
regulates functions of various organs
 little or no conscious control
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Two branches:
sympathetic
parasympathetic
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Biological Factors:
Basic Principles of Behaviour Genetics
dominant and recessive genes
genotype vs. phenotype
mental disorders, if inherited, are
most likely polygenic
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Biological Factors:
Researching Behaviour Genetics
family incidence studies
monozygotic (MZ) vs. dizygotic (DZ)
twins
adoption studies
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Nature/Nurture Debate
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genes alone do not cause most disorders
if crime is “genetic”, where is the “crime”
gene?
environment can maximize genetic potential
conclusion: nature and nurture are
inseparable influences
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Psychological Factors
1) Basic human motivations and
temperament
2) Emotion
3) Learning and cognition
4) Sense of self
5) Development
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1) Basic Human Motivations
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Evolutionary Psychology
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Attachment Theory
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human psychology has evolved based on the
principles of natural selection and inclusive fitness
disorders rooted in insecure or anxious
attachments
Temperament
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individual differences rated on “Big Five”
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2) Emotion
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six basic emotions:
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love
joy
surprise
anger
sadness
fear
controlled by subcortical brain
structures
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3) Learning and Cognition
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Modeling
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Albert Bandura (1925-)
behaviour by imitating others
Cognition
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human brain analogous to a computer
social cognition
attribution errors
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4) Sense of Self
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Erikson’s concept of identity
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George Kelly (1905-1966)
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people adhere to various roles throughout life
socialization
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quest to answer, “Who am I?”
learn societal rules and develop self-control
self-efficacy
self-esteem and mental health
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5) Development
 developmental transitions
 Freud’s psychosexual development
 Erikson’s psychosocial development
 Jean Piaget and cognitive development
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Social Factors
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Labeling Theory
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abnormal behaviour the product of social
expectations
self-fulfilling prophesy
Relationships
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marital status
social support a protective factor
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Social Factors
Gender roles
 Prejudice and poverty
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First Nations people living in cities are more than
twice as likely to live in poverty (Lee, 2000)
suffer substance abuse, family violence, risk for
suicide
Societal values
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