Chapter 2 Causes of Abnormal Behaviour: A Systems Approach Copyright © 2006 Pearson Education Canada Inc

Chapter 2Causes of Abnormal Behaviour:

A Systems Approach

Copyright © 2006 Pearson Education Canada Inc.

Copyright © 2006 Pearson Education Canada Inc. 2

Thinking About Abnormal Behaviour

What causes it?

How should we study it?

paradigms vs. systems theory


Paradigms

four traditional paradigms:– biological– psychodynamic– cognitive behavioural– humanistic

assumptions inflexible & sometimes too narrow


Systems Theory

integrative approach (biopsychosocial)holism vs. reductionismmultifactorial causescan not fully explain causes of most

abnormal behaviour


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


History of the Paradigms:Pre-20th Century

witchcraft

development of the scientific method


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


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



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


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



Systems Theory Revisited

Diathesis-stress model– disorders typically have several risk factors– equifinality – multifinality– reciprocal causality

Developmental psychopathology– utilizes developmental norms– allows for prognosis


Development of Psychopathology

Biological Factors

Psychological Factors

Social Factors


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



Biological Factors: Neural Networks

very complicated in the human brainchange as a function of experienceDonald Hebb (1904-1985)


Biological Factors:Brain Structures

hindbrain, midbrain, forebrainlimbic systemhypothalamus and thalamus


Biological Factors:Cerebral Hemispheres

lateralization of functioncoordination of function

– corpus callosum

four ventriclescerebral cortex

– frontal lobe– parietal lobe– temporal lobe– occipital lobe


Biological Factors:Endocrine System

release hormones into the bloodstream

regulates aspects of normal development


Biological Factors: Autonomic Nervous System (ANS)

regulates functions of various organslittle or no conscious control

Two branches:sympatheticparasympathetic


Biological Factors:Basic Principles of Behaviour Genetics

dominant and recessive genesgenotype vs. phenotypemental disorders, if inherited, are

most likely polygenic


Biological Factors:Researching Behaviour Genetics

family incidence studies

monozygotic (MZ) vs. dizygotic (DZ) twins

adoption studies


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


Psychological Factors

1) Basic human motivations and temperament

2) Emotion

3) Learning and cognition

4) Sense of self

5) Development


1) Basic Human Motivations

Evolutionary Psychology– human psychology has evolved based on the

principles of natural selection and inclusive fitness

Attachment Theory– disorders rooted in insecure or anxious

attachments

Temperament– individual differences rated on “Big Five”


2) Emotion

six basic emotions:– love– joy– surprise – anger– sadness – fear

controlled by subcortical brain structures


3) Learning and Cognition

Modeling– Albert Bandura (1925-)– behaviour by imitating others

Cognition– human brain analogous to a computer– social cognition– attribution errors


4) Sense of Self

Erikson’s concept of identity– quest to answer, “Who am I?”

George Kelly (1905-1966)– people adhere to various roles throughout life

socialization– learn societal rules and develop self-control

self-efficacy self-esteem and mental health


5) Development

developmental transitions

Freud’s psychosexual development

Erikson’s psychosocial development

Jean Piaget and cognitive development


Social Factors

Labeling Theory– abnormal behaviour the product of social

expectations– self-fulfilling prophesy

Relationships– marital status– social support a protective factor


Social Factors

Gender rolesPrejudice 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

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Chapter 2 Causes of Abnormal Behaviour: A Systems Approach Copyright © 2006 Pearson Education Canada Inc