Genetic Factors

Twin and Adoption Studies

Heritability (genetic) factors have been linked to aggressive behaviour with many studies focussing on twin and adoption studies.

Twin studies

Twin studies allow researchers to examine the role of genetics.
- Identical, or monozygotic (MZ) twins share 100% of their genes.
- Non-identical, or dizygotic (DZ) twins share 50% of their genes.
If a closer genetic relationship is related to higher or lower levels of aggression then aggression can be said to have a heritable component.

Coccaro et al. (1997)

Coccaro et al. (1997) studied aggressive behaviour (defined as direct physical assault) in adult male MZ and DZ twins.
They found concordance rates of:
- 50% for MZ twins.
- 19% for DZ twins.

Christiansen (1977)

Christiansen (1977) investigated the role of genetics in aggressive criminal behaviour.
Christiansen (1977) conducted a case study of 3500 twins in Denmark and looked at both MZ and DZ twins
For MZ male twins the concordance rate was 35% and MZ females 21%, compared to 13% DZ males and 8% DZ females.
Since MZ share 100% DNA this gives some support to the genetic explanation of aggressive behaviour.

Adoption studies

Adoption studies have found that similarities in aggressive behaviour between an adopted child and their biological parents.
This suggests that genetic influences are operating.
Similarities with the adoptive parents suggest that environmental factors also influence aggressive behaviour.

Rhee and Waldman (2002)

Rhee and Waldman (2002) carried out a meta analysis of adoption studies relating to direct aggression and antisocial behaviour.
They discovered that genetic influences accounted for 41% of the variance in aggression.
This is more or less in line with findings from twin studies.

The MAOA Gene

The MAOA gene could be linked to aggressive behaviour.

Catabolism

The MAOA, or monoamine oxidase A, is an enzyme whose role is to mop up neurotransmitters in the brain after nerve impulses have been transmitted from one neuron to another.
MAOA does this by breaking down the neurotransmitter (especially serotonin) into constituent chemicals to be recycled or excreted, a process known as catabolism.

Serotonin and MAOA

The production of the enzyme is determined by the MAOA gene and dysfunction in the operation of this gene may lead to abnormal activity of the MAOA enzyme.
This can affect serotonin levels in the brain.

The warrior gene

One variant of the MAOA gene, often known as the warrior gene, leads to low MAOA activity in certain areas of the brain.
This has been associated with various forms of aggressive behaviour.

Brunner et al. (1993)

Brunner et al. (1993) studied 28 members of a large Dutch family who were repeatedly involved in impulsive aggressive violent criminal behaviours such as rape, attempted murder and physical assault.
They found that these men had abnormally low levels of MAOA in their brains and the low activity version of the gene.

Cases et al (1995)

Cases et al (1995) provided evidence via an animal experimentation to support Brunner’s findings about the MAOA gene and its link to aggression.
Transgenic mice were studied who had a deletion in the gene that encodes MAOA.
MAOA deficient males showed increased aggressive behaviour.
This shows that MAOA deficiency is linked to aggression.

Stuart et al. (2014)

Stuart et al. (2014) studied 97 men who (because they had been involved in inflicting intimate partner violence) (IPV), were part of the batterer treatment program.
Men with the low activity MAOA gene were found to be the most violent perpetrators of IPV, engaging in the highest levels of physical and psychological aggression and inflicting the worst injuries on their partners.

Merins et al. (2011)

If the low activity variance of the MAOA gene is associated with greater aggression, then the converse must also be true.
Merins et al. (2011) studied participants with low-activity and high-activity variance of the MAOA gene in a money distributing game where participants had to contribute money for the good of the group.
The researchers found that males with a high-activity variant were more cooperative and made fewer aggressive moves than the low-activity participants.

Gene-Environment (GxE) Interaction

Genes interact with the environment to produce aggression; this is known as gene-environment (GxE) interaction.

MAOA and trauma

Genes influence aggressive behaviour but they do not function in isolation.
Low MAOA gene activity only appears to be related to adult aggression when combined with a early traumatic life events.

Frazzetto et al. (2007)

Frazzetto et al. (2007) found an association between higher levels of antisocial aggression and the low activity MAOA gene variant in adult males.
However this was only the case in those who had experienced significant trauma, such as sexual or physical abuse, during the first 15 years of life.

Conclusions

Those who had not experienced such childhood trauma did not have critically high levels of aggression as adults, even if they possessed the low-activity MAOA variant.
This would suggest a gene environment interaction or diatheses-stress.

1Social Influence

1.1Social Influence

1.1.1Conformity

1.1.2Asch (1951)

1.1.3Sherif (1935)

1.1.4Conformity to Social Roles

1.1.5BBC Prison Study

1.1.6End of Topic Test - Conformity

1.1.7Obedience

1.1.8Analysing Milgram's Experiment

1.1.9Agentic State & Legitimate Authority

1.1.10Variables of Obedience

1.1.11Resistance to Social Influence

1.1.12Minority Influence & Social Change

1.1.13Minority Influence & Social Impact Theory

1.1.14End of Topic Test - Social Influences

1.1.15Exam-Style Question - Conformity

1.1.16Top Grade AO2/AO3 - Social Influence

2Memory

3Attachment

3.1Attachment

3.1.1Caregiver-Infant Interaction

3.1.2Condon & Sander (1974)

3.1.3Schaffer & Emerson (1964)

3.1.4Multiple Attachments

3.1.5Studies on the Role of the Father

3.1.6Animal Studies of Attachment

3.1.7Explanations of Attachment

3.1.8Attachment Types - Strange Situation

3.1.9Cultural Differences in Attachment

3.1.10Disruption of Attachment

3.1.11Disruption of Attachment - Privation

3.1.12Overcoming the Effects of Disruption

3.1.13The Effects of Institutionalisation

3.1.14Early Attachment

3.1.15Critical Period of Attachment

3.1.16End of Topic Test - Attachment

3.1.17Exam-Style Question - Attachment

3.1.18Top Grade AO2/AO3 - Attachment

4Psychopathology

4.1Psychopathology

4.1.1Definitions of Abnormality

4.1.2Definitions of Abnormality 2

4.1.3Phobias, Depression & OCD

4.1.4Phobias: Behavioural Approach

4.1.5Evaluation of Behavioural Explanations of Phobias

4.1.6Depression: Cognitive Approach

4.1.7OCD: Biological Approach

4.1.8Evidence for the Biological Approach

4.1.9End of Topic Test - Psychopathy

4.1.10Exam-Style Question - Phobias

4.1.11Top Grade AO2/AO3 - Psychopathology

5Approaches in Psychology

5.1Approaches in Psychology

5.2Comparison of Approaches (A2 only)

5.2.1Psychodynamic Approach

5.2.2Cognitive Approach

5.2.3Biological Approach

5.2.4Behavioural Approach

5.2.5End of Topic Test - Comparison of Approaches

6Biopsychology

6.1Biopsychology

6.1.1Nervous System Divisions

6.1.2Neuron Structure & Function

6.1.3Neurotransmitters

6.1.4Endocrine System Function

6.1.5Fight or Flight Response

6.1.6The Brain (A2 only)

6.1.7Localisation of Brain Function (A2 only)

6.1.8Studying the Brain (A2 only)

6.1.9CIMT (A2 Only) & Postmortem Examinations

6.1.10Biological Rhythms (A2 only)

6.1.11Studies on Biological Rhythms (A2 Only)

6.1.12End of Topic Test - Biopsychology

6.1.13Top Grade AO2/AO3 - Biopsychology

7Research Methods

7.1Research Methods

7.1.1Experimental Method

7.1.2Observational Techniques

7.1.3Covert, Overt & Controlled Observation

7.1.4Self-Report Techniques

7.1.5Correlations

7.1.6Exam-Style Question - Research Methods

7.1.7End of Topic Test - Research Methods

7.2Scientific Processes

7.2.1Aims, Hypotheses & Sampling

7.2.2Pilot Studies & Design

7.2.3Questionnaires

7.2.4Variables & Control

7.2.5Demand Characteristics & Investigator Effects

7.2.6Ethics

7.2.7Limitations of Ethical Guidelines

7.2.8Consent & Protection from Harm Studies

7.2.9Peer Review & The Economy

7.2.10Validity (A2 only)

7.2.11Reliability (A2 only)

7.2.12Features of Science (A2 only)

7.2.13Paradigms & Falsifiability (A2 only)

7.2.14Scientific Report (A2 only)

7.2.15Scientific Report 2 (A2 only)

7.2.16End of Topic Test - Scientific Processes

7.3Data Handling & Analysis

7.3.1Types of Data

7.3.2Descriptive Statistics

7.3.3Correlation

7.3.4Evaluation of Descriptive Statistics

7.3.5Presentation & Display of Data

7.3.6Levels of Measurement (A2 only)

7.3.7Content Analysis (A2 only)

7.3.8Case Studies (A2 only)

7.3.9Thematic Analysis (A2 only)

7.3.10End of Topic Test - Data Handling & Analysis

7.4Inferential Testing

7.4.1Introduction to Inferential Testing

7.4.2Sign Test

7.4.3Piaget Conservation Experiment

7.4.4Non-Parametric Tests

8Issues & Debates in Psychology (A2 only)

8.1Issues & Debates in Psychology (A2 only)

8.1.1Culture Bias

8.1.2Sub-Culture Bias

8.1.3Gender Bias

8.1.4Ethnocentrism

8.1.5Cross Cultural Research

8.1.6Free Will & Determinism

8.1.7Comparison of Free Will & Determinism

8.1.8Reductionism & Holism

8.1.9Reductionist & Holistic Approaches

8.1.10Nature-Nurture Debate

8.1.11Interactionist Approach

8.1.12Nature-Nurture Methods

8.1.13Nature-Nurture Approaches

8.1.14Idiographic & Nomothetic Approaches

8.1.15Socially Sensitive Research

8.1.16End of Topic Test - Issues and Debates

9Option 1: Relationships (A2 only)

9.1Relationships: Sexual Relationships (A2 only)

9.1.1Sexual Selection & Human Reproductive Behaviour

9.1.2Intersexual & Intrasexual Selection

9.1.3Evaluation of Sexual Selection Behaviour

9.1.4Factors Affecting Attraction: Self-Disclosure

9.1.5Evaluation of Self-Disclosure Theory

9.1.6Self Disclosure in Computer Communication

9.1.7Factors Affecting Attraction: Physical Attributes

9.1.8Matching Hypothesis Studies

9.1.9Factors Affecting Physical Attraction

9.1.10Factors Affecting Attraction: Filter Theory 1

9.1.11Factors Affecting Attraction: Filter Theory 2

9.1.12Evaluation of Filter Theory

9.1.13End of Topic Test - Sexual Relationships

9.2Relationships: Romantic Relationships (A2 only)

9.2.1Social Exchange Theory

9.2.2Evaluation of Social Exchange Theory

9.2.3Equity Theory

9.2.4Evaluation of Equity Theory

9.2.5Rusbult’s Investment Model

9.2.6Evaluation of Rusbult's Investment Model

9.2.7Relationship Breakdown

9.2.8Studies on Relationship Breakdown

9.2.9Evaluation of Relationship Breakdown

9.2.10End of Topic Test - Romantic relationships

9.3Relationships: Virtual & Parasocial (A2 only)

9.3.1Virtual Relationships in Social Media

9.3.2Evaluation of Reduced Cues & Hyperpersonal

9.3.3Parasocial Relationships

9.3.4Attachment Theory & Parasocial Relationships

9.3.5Evaluation of Parasocial Relationship Theories

9.3.6End of Topic Test - Virtual & Parasocial Realtions

10Option 1: Gender (A2 only)

10.1Gender (A2 only)

10.1.1Sex, Gender & Androgyny

10.1.2Gender Identity Disorder

10.1.3Biological & Social Explanations of GID

10.1.4Biological Influences on Gender

10.1.5Effects of Hormones on Gender

10.1.6End of Topic Test - Gender 1

10.1.7Kohlberg’s Theory of Gender Constancy

10.1.8Evaluation of Kohlberg's Theory

10.1.9Gender Schema Theory

10.1.10Psychodynamic Approach to Gender Development 1

10.1.11Psychodynamic Approach to Gender Development 2

10.1.12Social Approach to Gender Development

10.1.13Criticisms of Social Theory

10.1.14End of Topic Test - Gender 2

10.1.15Media Influence on Gender Development

10.1.16Cross Cultural Research

10.1.17Childcare & Gender Roles

10.1.18End of Topic Test - Gender 3

11Option 1: Cognition & Development (A2 only)

11.1Cognition & Development (A2 only)

11.1.1Piaget’s Theory of Cognitive Development 1

11.1.2Piaget's Theory of Cognitive Development 2

11.1.3Schema Accommodation Assimilation & Equilibration

11.1.4Piaget & Inhelder’s Three Mountains Task (1956)

11.1.5Conservation & Class Inclusion

11.1.6Evaluation of Piaget

11.1.7End of Topic Test - Cognition & Development 1

11.1.8Vygotsky

11.1.9Evaluation of Vygotsky

11.1.10Baillargeon

11.1.11Baillargeon's studies

11.1.12Evaluation of Baillargeon

11.1.13End of Topic Test - Cognition & Development 2

11.1.14Sense of Self & Theory of Mind

11.1.15Baron-Cohen Studies

11.1.16Selman’s Five Levels of Perspective Taking

11.1.17Biological Basis of Social Cognition

11.1.18Evaluation of Biological Basis of Social Cognition

11.1.19Important Issues in Social Neuroscience

11.1.20End of Topic Test - Cognition & Development 3

11.1.21Top Grade AO2/AO3 - Cognition & Development

12Option 2: Schizophrenia (A2 only)

12.1Schizophrenia: Diagnosis (A2 only)

12.1.1Classification & Diagnosis

12.1.2Reliability & Validity of Diagnosis

12.1.3Gender & Cultural Bias

12.1.4Pinto (2017) & Copeland (1971)

12.1.5End of Topic Test - Scizophrenia Diagnosis

12.2Schizophrenia: Treatment (A2 only)

12.2.1Family-Based Psychological Explanations

12.2.2Evaluation of Family-Based Explanations

12.2.3Cognitive Explanations

12.2.4Drug Therapies

12.2.5Evaluation of Drug Therapies

12.2.6Biological Explanations for Schizophrenia

12.2.7Dopamine Hypothesis

12.2.8End of Topic Test - Schizoprenia Treatment 1

12.2.9Psychological Therapies 1

12.2.10Psychological Therapies 2

12.2.11Evaluation of Psychological Therapies

12.2.12Interactionist Approach - Diathesis-Stress Model

12.2.13Interactionist Approach - Triggers & Treatment

12.2.14Evaluation of the Interactionist Approach

12.2.15End of Topic Test - Scizophrenia Treatments 2

13Option 2: Eating Behaviour (A2 only)

13.1Eating Behaviour (A2 only)

13.1.1Explanations for Food Preferences

13.1.2Birch et al (1987) & Lowe et al (2004)

13.1.3Control of Eating Behaviours

13.1.4Control of Eating Behaviour: Leptin

13.1.5Biological Explanations for Anorexia Nervosa

13.1.6Psychological Explanations: Family Systems Theory

13.1.7Psychological Explanations: Social Learning Theory

13.1.8Psychological Explanations: Cognitive Theory

13.1.9Biological Explanations for Obesity

13.1.10Biological Explanations: Studies

13.1.11Psychological Explanations for Obesity

13.1.12Psychological Explanations: Studies

13.1.13End of Topic Test - Eating Behaviour

14Option 2: Stress (A2 only)

14.1Stress (A2 only)

14.1.1Physiology of Stress

14.1.2Role of Stress in Illness

14.1.3Role of Stress in Illness: Studies

14.1.4Social Readjustment Rating Scales

14.1.5Hassles & Uplifts Scales

14.1.6Stress, Workload & Control

14.1.7Stress Level Studies

14.1.8End of Topic Test - Stress 1

14.1.9Physiological Measures of Stress

14.1.10Individual Differences

14.1.11Stress & Gender

14.1.12Drug Therapy & Biofeedback for Stress

14.1.13Stress Inoculation Therapy

14.1.14Social Support & Stress

14.1.15End of Topic Test - Stress 2

15Option 3: Aggression (A2 only)

15.1Aggression: Physiological (A2 only)

15.1.1Neural Mechanisms

15.1.2Serotonin

15.1.3Hormonal Mechanisms

15.1.4Genetic Factors

15.1.5Genetic Factors 2

15.1.6End of Topic Test - Aggression: Physiological 1

15.1.7Ethological Explanation

15.1.8Innate Releasing Mechanisms & Fixed Action Pattern

15.1.9Evolutionary Explanations

15.1.10Buss et al (1992) - Sex Differences in Jealousy

15.1.11Evaluation of Evolutionary Explanations

15.1.12End of Topic Test - Aggression: Physiological 2

15.2Aggression: Social Psychological (A2 only)

15.2.1Social Psychological Explanation

15.2.2Buss (1963) - Frustration/Aggression

15.2.3Social Psychological Explanation 2

15.2.4Social Learning Theory (SLT) 1

15.2.5Social Learning Theory (SLT) 2

15.2.6Limitations of Social Learning Theory (SLT)

15.2.7Deindividuation

15.2.8Deindividuation 2

15.2.9Deindividuation - Diener et al (1976)

15.2.10End of Topic Test - Aggression: Social Psychology

15.2.11Institutional Aggression: Prisons

15.2.12Evaluation of Dispositional & Situational

15.2.13Influence of Computer Games

15.2.14Influence of Television

15.2.15Evaluation of Studies on Media

15.2.16Desensitisation & Disinhibition

15.2.17Cognitive Priming

15.2.18End of Topic Test - Aggression: Social Psychology

16Option 3: Forensic Psychology (A2 only)

17Option 3: Addiction (A2 only)

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