Biological basis of behaviour introduction

Here are detailed notes on the body-mind relationship in psychology, covering key concepts, theories, and relevance:

Body-Mind Relationship in Psychology

Definition

The body-mind relationship refers to the interaction between physical (biological) processes and mental (psychological) processes. It explores how thoughts, emotions, and behaviors are connected to the body—especially the brain and nervous system.

Historical Perspectives

Dualism

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• Mind and body are two distinct entities.

• The mind (non-material) governs thinking and consciousness.

• The body (material) operates like a machine.

• Interaction occurs through the pineal gland (according to Descartes).

  
  

Monism

• Mind and body are one; mental processes are the result of physical processes.

• Two types:

  • Materialistic Monism: Only the body (brain) exists; the mind is a product of brain activity.

  • Idealistic Monism: Only the mind exists; the body is an illusion.

    
    

Modern Views

Biopsychosocial Model

• Integrates biological, psychological, and social factors.

• Health and illness are outcomes of interactions between:

  • Biological factors (e.g., genes, neurochemistry)

  • Psychological factors (e.g., thoughts, emotions)

  • Social factors (e.g., relationships, culture)

    
    

Psychosomatic Approach

• Emphasizes that mental states can influence physical health.

• Examples:

  • Stress leading to headaches or ulcers.

  • Anxiety causing rapid heartbeat or gastrointestinal problems.

    
    

Key Theories and Concepts

Cognitive Neuroscience

• Studies how brain activity is linked to mental processes (e.g., memory, perception, language).

• Uses tools like fMRI, EEG to study brain-mind interactions.

  
  

Psychoneuroimmunology (PNI)

• Studies how the mind (stress, emotions) affects the immune system.

• Chronic stress weakens immunity, increasing vulnerability to illness.

  
  

Placebo Effect

• A person experiences improvement in health after receiving a non-active treatment, simply due to belief and expectation.

• Highlights how mental belief can influence physical outcomes.

  
  

Somatization

• The experience of psychological distress as physical symptoms.

• Common in anxiety and depression disorders.

  
  

Practical Applications

Mind-Body Therapies

• Yoga, meditation, and mindfulness help regulate emotions and reduce physical stress symptoms.

• Used in treating anxiety, chronic pain, hypertension, and depression.

  
  

Behavioral Medicine

Combines psychology and medicine to treat disorders like obesity, diabetes, and heart disease through behavioral change (e.g., diet, stress management)

Genetics and Behaviour – Detailed Notes (Psychology)

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Introduction to Genetics and Behaviour

• Genetics is the study of how traits are passed from parents to offspring through genes.

• Behavioural genetics examines the role of genetic and environmental influences on behaviour.

• Psychologists investigate how genes interact with the environment to shape behaviour, emotions, and cognition.

Key Concepts

Twin and Adoption Studies

These are major methods used to study the influence of genetics on behaviour.

• Twin Studies:

  • Compare monozygotic twins (identical, share 100% of genes) with dizygotic twins (fraternal, share ~50% of genes).

  • If monozygotic twins show more similarity in a trait than dizygotic twins, genetics likely plays a strong role.

    
    

• Adoption Studies:

  • Compare adopted children to their biological parents (genetics) and adoptive parents (environment).

  • Help separate environmental from genetic influences.

Example: Studies show that intelligence has a significant genetic component, but environment also plays a crucial role.

Epigenetics and Behaviour

• Epigenetic modifications (like DNA methylation) can turn genes “on” or “off.”

• These changes can be triggered by

  • Stress

  • Diet

  • Toxins

  • Parental care

• Example: Early childhood trauma can lead to epigenetic changes affecting stress hormone regulation.

  
  

Ethical Considerations

• Genetic research raises ethical questions:

  • Should we screen embryos for genetic traits?

  • Could genetic information be used to discriminate?

  • How do we balance genetic and environmental explanations without promoting determinism?

    
    

Conclusion

• Behaviour is influenced by a dynamic interaction between genes and environment.

• Genetics may predispose individuals to certain behaviours, but environment often determines how (or if) these traits are expressed.

  
  

Inheritance of Behaviour – Psychology Notes

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Introduction

• Inheritance of behaviour refers to how genetic information (from parents) influences the behaviour of offspring.

• Behavioural genetics is a field that investigates how genes and environment interact to shape behaviour.

  
  

Key Concepts

Methods to Study Inheritance of Behaviour

Twin Studies

• Compare monozygotic (MZ) and dizygotic (DZ) twins.

• MZ twins: Identical genetics (100%).

• DZ twins: Share ~50% of genes.

• If MZ twins are more similar in behaviour than DZ twins, genetics is likely a strong influence.

Example

• Bouchard et al. (1990) — Minnesota Twin Study:

  • MZ twins reared apart showed similar IQ levels (heritability of intelligence ≈ 70%).

    
    

Adoption Studies

• Compare adopted children to:

  • Biological parents (genetic influence).

  • Adoptive parents (environmental influence).

Example:

• Heston (1966): Children of mothers with schizophrenia adopted into healthy families still had higher risk of developing schizophrenia, showing a genetic component.

  
  

Family Studies

• Look at behaviour traits across several generations.

• Helpful in identifying patterns in mental illness, addictions, and personality traits.

  
  

Molecular Genetics

• Identifying specific genes linked to behaviour.

• Example: MAOA gene (“warrior gene”) linked to aggression, especially in those exposed to childhood abuse.

  
  

Epigenetics and Inheritance of Behaviour

• Epigenetics explains how gene expression is influenced by environment.

• Gene expression can be turned on or off due to environmental factors (stress, trauma, diet).

• These changes can sometimes be inherited.

Example:

• Weaver et al. (2004): Rats raised by nurturing mothers showed less stress in adulthood. Epigenetic changes in stress hormone receptors occurred, inherited across generations.

  
  

Ethical Considerations

• Genetic privacy: Who can access genetic data?

• Labeling: Risk of stigmatizing individuals based on genetic predispositions.

• Genetic determinism: Misuse of data in policy or social treatment.