1.11 - Anxiety & Fear-related Disorders: Explanations
Biological explanations of anxiety and fear-related disorders
Anxiety and fear-related disorders refer to conditions where individuals experience excessive fear or anxiety, often triggered by specific stimuli or situations. These can include phobias, which are intense, irrational fears of particular objects or scenarios. Biological explanations suggest that such disorders have a physical basis in the body, often linked to genetic factors.
Genetic inheritance
Genetic inheritance involves the passing down of traits from parents to offspring through genes, which are segments of DNA that code for specific characteristics. In the context of anxiety and fear-related disorders, research indicates that these conditions can be inherited, meaning certain genetic factors increase a person's vulnerability.
Evidence supporting genetic inheritance:
- Family and twin studies - These studies compare the occurrence of disorders among relatives.
- Concordance rates, which measure the likelihood that both individuals in a pair share the same trait, are higher in monozygotic (MZ) twins (who share 100% of their DNA) than in dizygotic (DZ) twins (who share about 50%).
- For example, MZ twins show a 39% concordance rate for anxiety disorders, compared to 9% for DZ twins.
- This suggests a genetic component, as the higher rate in MZ twins points to inherited factors rather than just shared environments.
- Genetic mutations - Changes in genes, such as duplication of the NTRK3 gene, may heighten risk. Over-expression of this gene, where it produces too much of its protein, has been linked to increased levels of noradrenaline, a neurotransmitter (chemical messenger in the brain) associated with stress and anxiety responses.
Research study: Öst (1992) on blood-injection phobia
This study examined whether blood phobia and injection phobia are similar enough to be classified as a single disorder, known as blood-injection phobia, by comparing their origins, symptoms, and biological responses.
Method
- Self-report data was collected from participants with blood phobia, injection phobia, or other phobias (such as animal phobias). This included details on phobia origins, age of onset, family history, and experiences of fainting.
- During exposure tasks, blood phobics watched a video of surgery, while injection phobics underwent a finger-prick test. Researchers measured:
- Time taken to withdraw from the task.
- Self-reported anxiety levels on a 0–10 scale.
- Physiological responses, including heart rate and blood pressure.
Results
- Blood phobics had more first-degree relatives (close family members like parents or siblings) with the same phobia compared to injection phobics.
- Blood phobics reported greater fear of fainting as a response to their phobia.
- Both groups showed similar levels of anxiety and withdrawal times during tasks.
- Physiological differences were noted:
| Aspect | Blood phobics | Injection phobics |
|---|---|---|
| Heart rate/blood pressure | Decrease | Increase |
| Likelihood of fainting | More likely | Less likely |
Conclusions
- Blood and injection phobics share more similarities than differences, supporting their classification as one phobia.
- However, blood phobia appears to have a stronger genetic basis and more intense biological reactions than injection phobia.
Evaluation
| Strengths | Limitations |
|---|---|
| High internal validity – Data from seven participants was excluded if they did not meet diagnostic criteria upon re-assessment, ensuring accurate grouping. | Low ecological validity – Watching a surgery video differs from real-life encounters with blood, potentially affecting how responses are generalised. |
| Use of objective data – Behavioural tests measured physical responses directly, avoiding reliance on subjective recall or imagination used in other studies. | Questionable validity – Reports of family history were not independently verified, so diagnoses in relatives might be inaccurate. |
Psychological explanations: behavioural approach
Psychological explanations focus on how thoughts, behaviours, and experiences contribute to anxiety and fear-related disorders. The behavioural approach emphasises learned responses, particularly through classical conditioning.
Classical conditioning
Classical conditioning is a learning process where a neutral stimulus (NS) becomes associated with an unconditioned stimulus (UCS) that naturally triggers a response, leading to a conditioned response (CR). For phobias, this means an originally harmless object or situation (NS) can provoke fear if paired with something frightening.
How classical conditioning explains phobias:
- Acquisition of phobias - If a person experiences a traumatic event (UCS, like a dog bite causing pain and fear), a nearby neutral stimulus (e.g., the sight of a dog as NS) may become linked to that fear. Over time, the NS alone emits the fear response, turning it into a conditioned stimulus (CS).
- Expectancy learning - Encountering the CS again can trigger the CR (fear) due to the learned expectation of danger. This explains why phobias persist even without repeated trauma.
Research study: Watson and Rayner (1920) on conditioned fear
This classic experiment, often called the "Little Albert" study, tested whether fear could be classically conditioned in a child and if it would generalise to similar stimuli.
Method
- A nine-month-old boy named Albert was observed in a controlled lab setting. His initial reactions to various stimuli were recorded, including animals (e.g., rat, rabbit) and non-animal objects (e.g., burning newspaper, building blocks, fur coat, cotton wool).
- Responses were filmed and noted qualitatively, focusing on behaviours like crying or avoidance.
- Conditioning involved presenting a white rat (NS) followed by a loud noise (UCS, which naturally caused fear). This pairing was repeated several times.
- Post-conditioning, Albert was tested with the rat and similar stimuli (other animals, white furry objects) in the same room and a different room.
Results
- Albert showed no initial fear towards any stimuli except the loud noise.
- After pairings, he developed fear of the rat alone, crying and trying to avoid it.
- The fear generalised to similar items, such as rabbits and fur coats, though it weakened over time without reinforcement.
- Some fear persisted when tested in a new room, indicating generalisation to different settings.
Conclusions
- Emotional responses like fear can be classically conditioned through association.
- Conditioned fears can extend to similar stimuli and environments, explaining how phobias spread.
Evaluation
| Strengths | Limitations |
|---|---|
| Longitudinal design – Multiple sessions tracked changes in Albert's responses over time, providing evidence that fear was learned rather than innate. | Low ecological validity – The lab setting was unfamiliar, which might have heightened responses; conditioning might be harder in everyday environments like home. |
| Rich qualitative data – Detailed observations of movements, expressions, and self-soothing behaviours offered deep insights into fear development. | Limited generalisability – Only one child was studied, and individual differences in temperament could affect how easily others condition. |
Psychological explanations: psychodynamic approach
The psychodynamic approach, developed by Sigmund Freud, views anxiety and fear-related disorders as arising from unconscious conflicts, often rooted in early childhood experiences.
Unresolved psychosexual conflicts
Psychosexual conflicts occur during Freud's stages of development, where innate drives (like those for sex and aggression) clash with societal norms. Unresolved issues, such as the Oedipus complex (where a boy unconsciously desires his mother and sees his father as a rival), can lead to phobias.
Defence mechanisms are used to protect against anxiety from these unconscious desires. The mind uses strategies like displacement, where fear is transferred from its true source (e.g., aggression towards a parent) to a safer object (e.g., an animal).
Research study: Freud (1909) on Little Hans
This case study explored how a child's horse phobia developed and resolved, using psychodynamic principles.
Method
- The subject was a five-year-old boy, Hans, with a phobia of white horses.
- Data was gathered through interviews with Hans and letters from his father to Freud, containing observations and Hans's statements.
Results
- Hans frequently discussed "widdlers" (penises), and his mother threatened to cut his off for touching it, which Freud linked to castration anxiety (fear of losing one's penis as punishment).
- Dreams were symbolic: One about giraffes represented the Oedipus complex, with the big giraffe as the father and the crumpled one as the mother. A later dream about a plumber was interpreted as the resolution of this complex, in which Hans identified with his father.
- The horse phobia was seen as displacement: The horse symbolised the father, onto whom castration anxiety was projected (e.g., fear of being bitten).
Conclusions
- Phobias express unconscious fears from unresolved conflicts like the Oedipus complex.
- Recovery involves resolving these conflicts, reducing the need for displacement.
Evaluation
| Strengths | Limitations |
|---|---|
| Rich qualitative data – Letters and interviews provided unique insights into Hans's thoughts that other methods couldn't capture. | Subjective bias – Data came mostly from the father's perspective, who might have selectively reported details aligning with Freud's interests. |
| Longitudinal approach – Spanning three years, it allowed tracking of fear changes, linking them to psychodynamic resolution. | Limited generalisability – Hans was from a specific cultural and socioeconomic background (wealthy Vienna family in the early 1900s), so findings may not apply to diverse modern children. |
Comparing biological and psychological explanations
Explanations for anxiety and fear-related disorders vary by approach, each with supporting evidence and limitations. The table below summarises key aspects.
| Approach | Explanation | Strengths | Weaknesses |
|---|---|---|---|
| Biological | Genetic inheritance increases vulnerability, e.g., NTRK3 gene duplication leads to higher noradrenaline and anxiety. | Strong evidence – 90% of those with fear disorders had NTRK3 duplication vs. 7% in controls; mouse studies show over-expression causes anxiety-like behaviours. Öst (1992) supports genetic links in blood phobia. | Reductionist – Ignores environmental influences on gene expression (epigenetics). Twin studies may confound genetics with shared environments. |
| Psychological (Behavioural) | Classical conditioning associates neutral stimuli with fear, creating conditioned responses. | Evidence from Watson and Rayner (1920) shows fear can be learned and generalised. Practical applications – Led to therapies like systematic desensitisation to unlearn fears. | Partial explanation – Does not account for why phobias resist extinction or why some fears (e.g., snakes) are learned more easily than others (e.g., flowers). |
| Psychological (Psychodynamic) | Unresolved unconscious conflicts (e.g., Oedipus complex) lead to displacement of fears onto phobic objects. | Evidence from Freud's (1909) Little Hans study links phobia to symbolic conflicts. Applications – Influenced modern talking therapies like cognitive behavioural therapy (CBT). | Unscientific and subjective – Concepts like the unconscious are hard to test; case studies involve bias and poor generalisability. |
Issues and debates in explanations of anxiety and fear-related disorders
Explanations of these disorders raise broader questions about human behaviour, such as the roles of choice, biology, and environment.
Determinism versus free will
- Determinism is the idea that behaviour is caused by forces beyond personal control.
- Biological explanations are deterministic, as genes like NTRK3 predetermine vulnerability to anxiety, limiting free will.
- Behavioural views are also deterministic, suggesting fears are inevitably learned from experiences, ignoring how cognitive interpretations (under conscious control) might alter outcomes.
- However, humans can exercise free will through choices like healthy lifestyles or therapy to mitigate these influences.
Nature versus nurture
- Nature refers to innate, biological factors, while nurture involves environmental influences.
- Traditional biological explanations emphasise nature (e.g., genetic mutations), but epigenetics shows how nurture can activate or silence genes, creating interactions that build resilience or heighten risk.
- Behavioural explanations focus on nurture (learned associations) but overlook nature, failing to explain twin study results.
- The psychodynamic approach integrates both: Innate drives (nature) interact with childhood experiences (nurture) to resolve or create conflicts.