Download Causes of Abnormal Behaviour

Chapter 2
Causes of Abnormal Behaviour:
A Systems Approach
Copyright © 2006 Pearson Education Canada Inc.
Thinking About Abnormal Behaviour

What causes it?

How should we study it?

paradigms vs. systems theory
Copyright © 2006 Pearson Education Canada Inc.
2
Paradigms

four traditional paradigms:
–
–
–
–

biological
psychodynamic
cognitive behavioural
humanistic
assumptions inflexible & sometimes too
narrow
Copyright © 2006 Pearson Education Canada Inc.
3
Systems Theory
integrative approach (biopsychosocial)
 holism vs. reductionism
 multifactorial causes
 can not fully explain causes of most
abnormal behaviour

Copyright © 2006 Pearson Education Canada Inc.
4
Case Study: Meghan’s Hardships


what caused Meghan to attempt suicide?
issues to consider:
–
–
–
–
–
–
heredity
inter-uterine problems
early physical abuse and neglect
rejection from peers
failure at school
difficult relationship with her adoptive mother
Copyright © 2006 Pearson Education Canada Inc.
5
History of the Paradigms:
Pre-20th Century
 witchcraft
 development
of the scientific
method
Copyright © 2006 Pearson Education Canada Inc.
6
History of the Paradigms:
Biological

cure of “general paresis”
–
–
–
–
–
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
Copyright © 2006 Pearson Education Canada Inc.
7
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

Copyright © 2006 Pearson Education Canada Inc.
8
Copyright © 2006 Pearson Education Canada Inc.
History of the Paradigms:
Cognitive Behavioural





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
Copyright © 2006 Pearson Education Canada Inc.
10
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
Copyright © 2006 Pearson Education Canada Inc.
11
Copyright © 2006 Pearson Education Canada Inc.
Systems Theory Revisited
 Diathesis-stress
–
–
–
–
disorders typically have several risk factors
equifinality
multifinality
reciprocal causality
 Developmental
–
–
model
psychopathology
utilizes developmental norms
allows for prognosis
Copyright © 2006 Pearson Education Canada Inc.
13
Development of Psychopathology
Biological Factors
Psychological Factors
Social Factors
Copyright © 2006 Pearson Education Canada Inc.
14
Biological Factors:
Neurons & Neurotransmitters

Neurons
–
–

smallest anatomic unit within the nervous system
dendrites →soma →axon →terminals→ synapse
Neurotransmitters
–
–
–
released into the synapse by axon terminals
trigger receptors on dendrites
over or undersupply linked to mental disorder
Copyright © 2006 Pearson Education Canada Inc.
15
Copyright © 2006 Pearson Education Canada Inc.
16
Biological Factors:
Neural Networks
very complicated in the human brain
change as a function of experience
Donald Hebb (1904-1985)
Copyright © 2006 Pearson Education Canada Inc.
17
Biological Factors:
Brain Structures
hindbrain, midbrain, forebrain
limbic system
hypothalamus and thalamus
Copyright © 2006 Pearson Education Canada Inc.
18
Biological Factors:
Cerebral Hemispheres
lateralization of function
 coordination of function

–
corpus callosum
four ventricles
 cerebral cortex

–
–
–
–
frontal lobe
parietal lobe
temporal lobe
occipital lobe
Copyright © 2006 Pearson Education Canada Inc.
19
Biological Factors:
Endocrine System
release hormones into the
bloodstream
regulates aspects of normal
development
Copyright © 2006 Pearson Education Canada Inc.
20
Biological Factors:
Autonomic Nervous System (ANS)
regulates functions of various organs
 little or no conscious control

Two branches:
sympathetic
parasympathetic
Copyright © 2006 Pearson Education Canada Inc.
21
Biological Factors:
Basic Principles of Behaviour Genetics
dominant and recessive genes
genotype vs. phenotype
mental disorders, if inherited, are
most likely polygenic
Copyright © 2006 Pearson Education Canada Inc.
22
Biological Factors:
Researching Behaviour Genetics
family incidence studies
monozygotic (MZ) vs. dizygotic (DZ)
twins
adoption studies
Copyright © 2006 Pearson Education Canada Inc.
23
Nature/Nurture Debate



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
Copyright © 2006 Pearson Education Canada Inc.
24
Psychological Factors
1) Basic human motivations and
temperament
2) Emotion
3) Learning and cognition
4) Sense of self
5) Development
Copyright © 2006 Pearson Education Canada Inc.
25
1) Basic Human Motivations

Evolutionary Psychology
–

Attachment Theory
–

human psychology has evolved based on the
principles of natural selection and inclusive fitness
disorders rooted in insecure or anxious
attachments
Temperament
–
individual differences rated on “Big Five”
Copyright © 2006 Pearson Education Canada Inc.
26
2) Emotion

six basic emotions:
–
–
–
–
–
–

love
joy
surprise
anger
sadness
fear
controlled by subcortical brain
structures
Copyright © 2006 Pearson Education Canada Inc.
27
3) Learning and Cognition

Modeling
–
–

Albert Bandura (1925-)
behaviour by imitating others
Cognition
–
–
–
human brain analogous to a computer
social cognition
attribution errors
Copyright © 2006 Pearson Education Canada Inc.
28
4) Sense of Self

Erikson’s concept of identity
–

George Kelly (1905-1966)
–


people adhere to various roles throughout life
socialization
–

quest to answer, “Who am I?”
learn societal rules and develop self-control
self-efficacy
self-esteem and mental health
Copyright © 2006 Pearson Education Canada Inc.
29
5) Development
 developmental transitions
 Freud’s psychosexual development
 Erikson’s psychosocial development
 Jean Piaget and cognitive development
Copyright © 2006 Pearson Education Canada Inc.
30
Social Factors

Labeling Theory
–
–

abnormal behaviour the product of social
expectations
self-fulfilling prophesy
Relationships
–
–
marital status
social support a protective factor
Copyright © 2006 Pearson Education Canada Inc.
31
Social Factors
Gender roles
 Prejudice and poverty

–
–

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
Copyright © 2006 Pearson Education Canada Inc.
32