CHAPTER TWO Causes of Abnormal Behavior: A Systems Approach

Causes of Abnormal Behavior What are paradigms? 4 basic psychological paradigms Behavior genetics Systems theory

What is a Paradigm? A set of shared assumptions about: the substance of a theory how scientists should collect data and test theoretical propositions.

Causes of Abnormal Behavior

4 Basic Psychological Paradigms Psychodynamic Cognitive-Behavioral Humanistic Biological

Which paradigm is correct? The blind men and the elephant

Which paradigm is correct? Two answers: Individually, all of them Some or all of them together This approach is a Systems theory or biopsychosocial approach

Causes of Abnormal Behavior

Systems Theory: Outline Definition Causality Levels of Analysis

Systems Theory: Definition No one paradigm offers the “right” approach. Systems theory integrates evidence from the biological, psychological and social domains. The centerpiece of systems theory is: Holism: whole=more than the sum of parts e.g. playing in a sports team (basketball, volleyball) The opposite of holism is: Reductionism: whole = sum of its parts. e.g. playing in a sports team (gymnastics, wrestling)

Diathesis-Stress Model Diathesis: existing vulnerability that precedes stressor Stress: any event that triggers the onset of disturbance A diathesis may or may not be biological, and a stressor may or may not be environmental. Systems Theory: Causality

Equifinality: different causes for same disorder Death of parent Loss of job Change in brain chemistry Depression

Systems Theory: Causality Multifinality: same causal factor but different outcomes Earthquake Phobia PTSD Depression

Reciprocal causality: causality is bidirectional. Parent’s behavior Child’s behavior Systems Theory: Causality

Systems Theory: Levels of Analysis Systems theory integrates evidence from biological, psychological and social domains of behavior (not additive) Different paradigms operate at different levels of analysis when explaining human behavior: e.g., neuron, individual, couple, family, community, culture.

Multidimensional Model 50% of psychology due to biological factors, 50% due to social factors?? Misleading… Because interactions between factors are more important

Causes of Abnormal Behavior

Behavior genetics the study of genetic contributions to the development of normal and abnormal behaviors Genotype total genetic make-up (genetic profile) Biological Paradigm: Behavior Genetics

Phenotype observable expression/characteristics of genotype (such as weight and eye color) Genotype is fixed at birth, but phenotype is a result of genotype and experiences. Biological Paradigm: Behavior Genetics

Genotype vs. Phenotype

There are three different approaches to studying behavior genetics. Family incidence studies Twin studies Adoption studies Biological Paradigm: Behavior Genetics

Family Incidence Studies: Do disorders run in families? Researchers identify the index person in a family or a proband Then examine the proportion of family members that suffer from different disorders relative to this person (the proband) Biological Paradigm: Behavior Genetics

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Biological Paradigm: Behavior Genetics *Are members of my family at risk for having a disorder given that I have the disorder?

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Biological Paradigm: Behavior Genetics

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Biological Paradigm: Behavior Genetics

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Biological Paradigm: Behavior Genetics

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Biological Paradigm: Behavior Genetics

Twin Studies: Logic Twin studies Concordance, simply means “agreement” Depressed Twin A = Depressed Twin B Example: in a study of 100 Twins, if 60% of all the twins both have depression, then the concordance rate is 60% MZ twins have 100% genetic overlap. On average, DZ twins have 50% genetic overlap (like typical siblings)

Assumes that pairs of MZ twins are not treated any more alike than are pairs of DZ twins But MZ twins may be treated more alike because they look alike… Twin Studies: Shortcoming

Twin Studies: Twins Raised Apart (MZ twins) To account for the fact that MZ twins may be treated more similarly than DZ Different adoptive families (= different environment or different treatment) Differences in concordance rates cannot be attributed to MZ twins having a more similar environment than DZ Can’t assume similar treatment of MZ twins, so if differences are found they may be attributed to environmental factors…

Behavior Genetics: Adoption Studies Compare adopted children with and without family histories of a disorder Compare concordance rates with biological and adoptive parents to see which is higher Genetic and environmental factors

Adoption Study: Disorder X Proband % Adopted-Away children (Biological Parents) with Disorder With Disorder X 20 Without Disorder X 10

Adoption Study: Disorder X Proband % Adopted-Away children (Biological Parents) with Disorder With Disorder X 20 Without Disorder X 10 * Children of Bio Parents with Disorder X are at a higher risk, so there is a Genetic Influence

Adoption Study: Disorder Y Proband % Adopted-Away children (Biological Parents) with Disorder With Disorder Y 10 Without Disorder Y 10

Adoption Study: Disorder X Proband % Adopted-Away children (Biological Parents) with Disorder With Disorder Y 10 Without Disorder Y 10 * Children of Bio Parents with Disorder Y are NOT at a higher risk, so there’s NO Genetic Influence

Adoption Study: Disorder X % biological % adoptive Proband parents with parents with Disorder X Adoptees with2010 Disorder X Adoptees without1010 Disorder X

Adoption Study: Disorder X % biological % adoptive Proband parents with parents with Disorder X Adoptees with2010 Disorder X Adoptees without1010 Disorder X * Bio Parents of children with Disorder X are at a higher risk compared to Adoptive Parents, so there is a Genetic Influence

Adoption Study: Disorder Y % biological % adoptive Proband parents with parents with Disorder Y Adoptees with1010 Disorder Y Adoptees without1010 Disorder Y

Adoption Study: Disorder Y % biological % adoptive Proband parents with parents with Disorder Y Adoptees with1010 Disorder Y Adoptees without1010 Disorder Y * Bio Parents of children with Disorder Y are NOT at a higher risk compared to Adoptive Parents, so there’s NO Genetic Influence

Adoption Study: Disorder Z % biological % adoptive Proband parents with parents with Disorder Z Adoptees with2010 Disorder Z Adoptees without2010 Disorder Z

Adoption Study: Disorder Z % biological % adoptive Proband parents with parents with Disorder Z Adoptees with2010 Disorder Z Adoptees without2010 Disorder Z * Bio Parents of children with Disorder Z are NOT at a higher risk compared to Bio Parents of children without Disorder Z, so there’s NO Genetic Influence

Genes not sufficient to account for development of any psychological disorder. We need to study environmental factors Gene-environment interactions: Reciprocal gene-environment model Genes might influence the environment that people seek out. Environmental factors may bring out a genetic predisposition. The two are not independent. Biological Paradigm: Behavior Genetics

Misinterpretation of Behavior Genetics INCORRECT ASSUMPTIONS If there is a genetic influence, a disorder is inevitable If a behavior or characteristic is genetically influenced, it cannot be changed If there is a genetic influence, a gene must be directly responsible for the behavior i.e., environmental factors are often necessary to trigger the expression of genes e.g., some people have genetic predisposition to alcohol, but they are still able to change polygenetic + environmental stress

Biology can be influenced by psychology! Biological causes do not necessarily require biological treatment Today most psychologists view disorders as being caused by multiple factors. Biological Perspective

Optional Slides

CHAPTER TWO (review) Causes of Abnormal Behavior: A Systems Approach

Review of Chapter Two A paradigm is a set of assumptions regarding how the things work. Four basic paradigms… Behavior genetics is a way of broadly studying genetic contributions to behavior. Genotypes and phenotypes

Genotype our actual genetic structure (biological make- up) Phenotypes observable expression/characteristics of genotype (such as weight and eye color) Genotype is fixed at birth, but phenotype is a result of genotype and experiences. Review of Chapter Two

There are three different approaches to studying behavior genetics. Family incidence studies Twin studies Adoption studies (proband) (concordance) (proband + concordance bet. twins) Review of Chapter Two

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Review of Chapter Two Family Incidence Studies: Do disorders run in families? Are members of my family at risk for having a disorder given that I have the disorder? Proband: Me

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Review of Chapter Two

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Review of Chapter Two

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Review of Chapter Two

Proband %family MDD %family Schz. MDD Schizophrenia No diagnosis Hypothetical Data Set Review of Chapter Two

TWIN STUDIES: RAISED TOGETHER Concordance: the percent of agreement between twins. Depressed Twin A = Depressed Twin B Example: in a study of 100 Twins, if 60% of all the twins both have depression, then the concordance rate is 60% MZ twins have 100% genetic overlap. On average, DZ twins have 50% genetic overlap (like typical siblings) Review of Chapter Two

Problem with Twin Studies Raised Together: Assumes that pairs of DZ twins are treated similarly as MZ twins But MZ twins may be treated more alike because they look alike… MZ TWIN STUDIES RAISED APART Different adoptive families (environment) Can’t assume similar treatment of MZ twins, so if differences are found they may be attributed to environmental factors… Review of Chapter Two

ADOPTION STUDIES Accounts for both genetic and environmental factors Compare adopted children with and without family histories of a disorder Review of Chapter Two

Proband % Adopted-Away children (Biological Parents) with Disorder With Disorder X 20 Without Disorder X 10 THESE ARE CONCORDANCE RATES Review of Chapter Two

Proband % Adopted-Away children (Biological Parents) with Disorder With Disorder X 20 Without Disorder X 10 Review of Chapter Two

Proband % Adopted-Away children (Biological Parents) with Disorder With Disorder Y 10 Without Disorder Y 10 Review of Chapter Two

Proband % Adopted-Away children (Biological Parents) with Disorder With Disorder Y 10 Without Disorder Y 10 Review of Chapter Two

ADOPTION STUDIES also… Compares concordance rates between: proband and biological parents proband and adoptive parents …to see which concordance rate is higher Review of Chapter Two

Adoption Study: Disorder X % biological % adoptive Proband parents with parents with Disorder X Adoptees with2010 Disorder X Adoptees without1010 Disorder X

% biological % adoptive Proband parents with parents with Disorder X Adoptees with2010 Disorder X Adoptees without1010 Disorder X Review of Chapter Two

% biological % adoptive Proband parents with parents with Disorder X Adoptees with1010 Disorder Y Adoptees without1010 Disorder Y Review of Chapter Two

% biological % adoptive Proband parents with parents with Disorder X Adoptees with1010 Disorder Y Adoptees without1010 Disorder Y Review of Chapter Two

INCORRECT ASSUMPTIONS (argument against in yellow) If there is a genetic influence, a disorder is inevitable (environmental factors are often necessary to trigger the expression of genes) If a behavior or characteristic is genetically influenced, it cannot be changed (some people have genetic predisposition to alcohol, but they are still able to change) If there is a genetic influence, a gene must be directly responsible for the behavior (polygenetic + environmental stress) Review of Chapter Two

Biology can be influenced by psychology! Biological causes do not necessarily require biological treatment Today most psychologists view disorders as being caused by multiple factors. Review of Chapter Two

Systems Theory: Definition No one paradigm offers the “right” approach. Systems theory integrates evidence from the biological, psychological and social domains. The centerpiece of systems theory is: Holism: whole=more than the sum of parts The opposite of holism is: Reductionism: whole = sum of its parts.

Diathesis-Stress Model Diathesis: existing vulnerability that precedes stressor Stress: any event that triggers the onset of disturbance A diathesis may or may not be biological, and a stressor may or may not be environmental. Systems Theory: Causality

Equifinality: different causes for same disorder Death of parent Loss of job Change in brain chemistry Depression

Systems Theory: Causality Multifinality: same causal factor but different outcomes Earthquake Phobia PTSD Depression

Reciprocal causality: causality is bidirectional. Parent’s behavior Child’s behavior Systems Theory: Causality

Systems Theory: Levels of Analysis Systems theory integrates evidence from biological, psychological and social domains of behavior Different paradigms operate at different levels of analysis when explaining human behavior: e.g., neuron, individual, couple, family, community, culture.