The two-process model of phobias | AQA A-Level Psychology Revision

Revision Notes

Aug 3

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Updated: Sep 9

For 7182 specification, first teach in September 2025

AQA A-Level Psychology | Free Revision Notes

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These Two-process model of phobias A-Level Psychology revision notes explain Mowrer’s behavioural account of how phobias develop and continue. The first process is classical conditioning, in which a previously neutral stimulus becomes associated with fear. The second is operant conditioning, in which avoidance is maintained because escaping the feared stimulus reduces anxiety. You will learn to apply each stage accurately, explain stimulus generalisation and evaluate the model using research evidence, biological preparedness, cognitive factors and behaviour-based treatments.

The AQA specification requires the two-process model, including both classical and operant conditioning.

Learning Objectives 🎯

By the end of this revision page, you should be able to:

Explain how a phobia may be acquired through classical conditioning.
Identify the neutral stimulus, unconditioned stimulus, unconditioned response, conditioned stimulus and conditioned response.
Explain stimulus generalisation.
Explain how avoidance maintains a phobia through operant conditioning.
Explain the role of negative reinforcement.
Apply both processes to unfamiliar phobia scenarios.
Evaluate the two-process model using evidence, alternative explanations and practical applications.

Revision Notes 📚

Two-process model of phobias A-Level Psychology revision overview

The two-process model was proposed by Mowrer as a behavioural explanation of phobias.

It is called the two-process model because it uses two forms of learning:

Classical conditioning explains the acquisition of a phobia.
Operant conditioning explains the maintenance of a phobia.

The basic model is:

A phobia is acquired through association and maintained through reinforcement.

Acquisition and maintenance

Acquisition means the original development or learning of the phobia.

Maintenance means the continuation of the phobia after it has developed.

The distinction is essential:

Stage	Learning process	What happens?
Acquisition	Classical conditioning	A previously neutral stimulus becomes associated with fear
Maintenance	Operant conditioning	Avoidance is reinforced because it removes anxiety

A strong answer explains both stages rather than treating the model as one continuous process.

The behavioural approach

The two-process model belongs to the behavioural approach.

Behaviourists argue that:

Behaviour is learned through experience.
Learning follows principles that can be observed and studied scientifically.
Environmental events are important.
Phobic behaviour can be understood without referring to unconscious conflict.
Behaviour learned through conditioning may also be changed through learning.

The broader principles are developed in basic assumptions of learning through observable behaviour.

Process one: classical conditioning

What is classical conditioning?

Classical conditioning is learning through association.

A stimulus that initially produces no fear becomes associated with a stimulus that naturally produces fear.

After the association has been learned, the previously neutral stimulus produces fear by itself.

The process involves:

A neutral stimulus.
An unconditioned stimulus.
An unconditioned response.
A conditioned stimulus.
A conditioned response.

The five essential terms

Term	Abbreviation	Meaning
Neutral stimulus	NS	A stimulus that does not initially produce the relevant fear response
Unconditioned stimulus	UCS	A stimulus that naturally produces fear or distress
Unconditioned response	UCR	The natural fear response produced by the UCS
Conditioned stimulus	CS	The previously neutral stimulus after association with the UCS
Conditioned response	CR	The learned fear response produced by the CS

Unconditioned means unlearned

An unconditioned response occurs naturally.

It does not need to be learned through the particular association.

For example:

Pain naturally produces fear.
A sudden frightening noise naturally produces distress.
Being knocked over may naturally produce shock and fear.

Conditioned means learned

A conditioned response develops through learning.

The person becomes afraid of a stimulus that was previously neutral because it has been associated with a frightening event.

Classical conditioning in three stages

Before conditioning

Before conditioning:

Neutral stimulus → no fear response

and:

Unconditioned stimulus → unconditioned fear response

For example:

Dog → no fear

Pain from being knocked over → fear

At this point, the dog is a neutral stimulus because it does not yet produce fear.

The pain and shock naturally produce fear, so they are the unconditioned stimulus.

During conditioning

During conditioning, the neutral stimulus and unconditioned stimulus occur together:

Dog + painful accident → fear

The person associates the dog with pain and shock.

The association may develop through:

One particularly frightening experience.
Several similar experiences.
Repeated pairings over time.

After conditioning

After conditioning:

Dog → fear

The dog has become a conditioned stimulus.

The fear of the dog is now a conditioned response.

The person has learned to fear the dog even when it is calm and presents little genuine danger.

Worked example: fear of dogs

Imagine that Charlie previously felt comfortable around dogs.

One day, a dog knocks Charlie over and Charlie breaks an arm.

Before conditioning

Element	Example
Neutral stimulus	Dog
Unconditioned stimulus	Pain and shock from the accident
Unconditioned response	Fear caused naturally by the pain and shock

During conditioning

Dog + pain and shock → fear

The dog and frightening accident are associated because they occur together.

After conditioning

Element	Example
Conditioned stimulus	Dog
Conditioned response	Fear when seeing a dog

Charlie may now become frightened by dogs even when no accident occurs.

Exam-ready explanation

The dog was initially a neutral stimulus. The pain and shock of the accident acted as an unconditioned stimulus and naturally produced fear, the unconditioned response. Through association, the dog became a conditioned stimulus that produced fear as a conditioned response.

Worked example: fear of the sea

Imagine that Max is carried away from the beach by a strong tide.

Before conditioning

The sea is a neutral stimulus.
Being carried away and believing that he may drown is the unconditioned stimulus.
Fear and panic are the unconditioned response.

During conditioning

The sea is experienced at the same time as the frightening event.

Sea + being carried away by the tide → fear

After conditioning

The sea becomes a conditioned stimulus.

Seeing or approaching the sea produces a conditioned fear response.

The official November 2020 AQA mark scheme used this kind of sequence when applying the two-process model to a fear of the sea.

One-trial learning

What is one-trial learning?

A powerful association may sometimes develop after one frightening experience.

This is known as one-trial learning.

For example:

One dog attack may produce a lasting fear of dogs.
One frightening flight may produce a fear of air travel.
One painful injection may produce a fear of needles.
One period trapped in a lift may produce a fear of enclosed spaces.

The experience may be especially influential when it is:

Intense.
Unexpected.
Painful.
Difficult to escape.
Perceived as life-threatening.

Conditioning does not always require repetition

Classical conditioning is often explained through repeated pairings.

However, highly frightening experiences may create an association rapidly.

This helps explain why some people can identify one event that appears to have started their phobia.

One event does not always create a phobia

Many people experience frightening events without developing phobias.

This creates an important limitation.

The outcome may also depend on:

Biological preparedness.
Previous learning.
Temperament.
Social support.
Interpretation of the event.
Later experiences.
Whether avoidance develops.

Stimulus generalisation

What is stimulus generalisation?

Stimulus generalisation occurs when the conditioned fear response spreads to stimuli similar to the original conditioned stimulus.

For example, somebody frightened by one large dog may later fear:

Other large dogs.
Small dogs.
Photographs of dogs.
Barking sounds.
Parks where dogs may be present.
Animals with similar features.

The fear is no longer limited to the exact stimulus involved in the original experience.

Generalisation in the sea example

Max may initially fear the specific beach where he was carried away by the tide.

The fear could generalise to:

Other beaches.
Swimming pools.
Boats.
Seaside holidays.
Photographs or videos of the sea.

Generalisation increases disruption

A narrowly focused fear may affect one situation.

A generalised fear may restrict many areas of life.

For example:

Fear of one dog → fear of all dogs → avoidance of parks → avoidance of friends with pets → reduced social activity

Similarity matters

Generalisation is more likely when another stimulus resembles the original conditioned stimulus.

However, generalisation can also be based on the person’s interpretation.

For example, a person may place:

Dogs.
Wolves.
Foxes.

within the same broad category of dangerous animals.

Little Albert

Watson and Rayner’s study

Watson and Rayner demonstrated how a fear response could be learned through classical conditioning.

A young child known as Little Albert initially showed little fear of a white rat.

A loud noise naturally produced distress.

The researchers repeatedly presented the rat with the loud noise.

Before conditioning

White rat: neutral stimulus.
Loud noise: unconditioned stimulus.
Fear caused by the noise: unconditioned response.

During conditioning

White rat + loud noise → fear

After conditioning

White rat: conditioned stimulus.
Fear of the rat: conditioned response.

Albert later showed fear towards other furry or white objects.

This suggests stimulus generalisation.

Why Little Albert supports the model

The study demonstrates that:

A previously neutral object can become feared.
Fear can be learned through association.
The fear response can generalise.

This supports the first process of the model.

Limitations of Little Albert as evidence

The evidence must be interpreted cautiously because:

It involved one child.
The conditioning occurred in a highly controlled situation.
The procedure deliberately caused distress.
Historical records do not provide complete certainty about Albert’s later development.
The study demonstrates that conditioning can occur, but not that all naturally occurring phobias develop this way.

Methodological criticism gains value only when linked to what it means for the explanation.

For example:

Evidence from one child cannot establish that classical conditioning explains the acquisition of every type of phobia.

Process two: operant conditioning

What is operant conditioning?

Operant conditioning is learning through the consequences of behaviour.

A behaviour becomes more or less likely depending on what follows it.

In the two-process model:

The person avoids or escapes the phobic stimulus.
Avoidance removes anxiety.
This relief reinforces the avoidance.
The person becomes more likely to avoid the stimulus again.

The principles are developed further in how consequences shape behaviour.

Negative reinforcement

What is negative reinforcement?

Negative reinforcement occurs when a behaviour removes an unpleasant stimulus or experience, making the behaviour more likely to be repeated.

In phobias:

The behaviour is avoidance.
The unpleasant experience is fear or anxiety.
Avoidance removes or reduces the anxiety.
The relief reinforces avoidance.

The pattern is:

Phobic stimulus → anxiety → avoidance → relief → increased future avoidance

Negative does not mean bad

In operant conditioning, negative means that something is removed.

It does not mean that the behaviour is morally wrong or that the outcome is harmful.

Reinforcement means behaviour increases

A consequence is a reinforcer when it makes the behaviour more likely to happen again.

Therefore:

Anxiety is removed.
Avoidance increases.
This is negative reinforcement.

It is not punishment

Punishment aims to reduce behaviour.

Negative reinforcement increases behaviour by removing something unpleasant.

Process	What happens?	Effect on behaviour
Negative reinforcement	Something unpleasant is removed	Behaviour increases
Punishment	An unpleasant consequence follows behaviour, or something desirable is removed	Behaviour decreases

Worked example: avoiding dogs

Charlie sees a dog and experiences fear.

Charlie crosses the road.

The fear decreases.

The reduction in fear is experienced as relief.

This relief negatively reinforces crossing the road.

The next time Charlie sees a dog, avoidance is more likely.

The maintenance cycle

Charlie sees a dog.
Charlie experiences anxiety.
Charlie crosses the road.
The dog is no longer nearby.
Anxiety decreases.
Crossing the road is reinforced.
Future avoidance becomes more likely.

The phobia continues even though the dog may have been harmless.

Escape and avoidance

Escape behaviour

Escape behaviour occurs when the person leaves after encountering the feared stimulus.

For example:

Leaving a room after seeing a spider.
Getting out of a lift when anxiety begins.
Running away from a dog.
Ending a medical appointment.

Avoidance behaviour

Avoidance behaviour occurs when the person prevents the encounter.

For example:

Refusing to enter the room.
Always using the stairs.
Avoiding parks.
Cancelling the medical appointment.

Both can be negatively reinforced because they reduce anxiety.

Example

Behaviour	Description
Seeing a spider and leaving the room	Escape
Refusing to enter any room where a spider was reported	Avoidance

Anticipatory avoidance

A person may avoid a situation long before the phobic stimulus appears.

For example, somebody with a fear of flying may:

Refuse to book a flight.
Decline a job involving travel.
Avoid discussions about overseas holidays.
Cancel a journey several weeks beforehand.

The person experiences relief as soon as the feared plan is removed.

That immediate relief may reinforce the decision to avoid.

Avoidance prevents extinction

What is extinction?

In classical conditioning, extinction occurs when the conditioned stimulus is repeatedly experienced without the unconditioned stimulus.

For example:

The person encounters a calm dog.
No attack occurs.
Repeated safe experiences may gradually weaken the conditioned fear.

Avoidance blocks safe learning

If the person always avoids dogs, they do not discover that:

Most dogs will not attack.
Anxiety may decrease naturally.
They can cope with being near a dog.
The feared outcome does not occur.

Avoidance therefore prevents the conditioned response from being extinguished.

The maintenance loop

Fear causes avoidance → avoidance prevents safe exposure → the fear remains → future avoidance continues

This is a particularly important reason why phobias can continue for years after the original frightening event.

Safety behaviours

What are safety behaviours?

A safety behaviour is an action used to feel protected while remaining in or near the feared situation.

Examples include:

Standing beside an exit.
Remaining close to a trusted person.
Carrying an object believed to provide protection.
Constantly checking for the feared stimulus.
Refusing to look away from a possible danger.

Safety behaviours may reduce anxiety temporarily.

The person may then conclude:

“Nothing bad happened because I used the safety behaviour.”

They do not learn that the situation may have been safe without it.

Safety behaviour and negative reinforcement

Safety behaviours can be negatively reinforced because they reduce fear.

However, cognitive beliefs may also be involved.

The person may believe that the behaviour actively prevents danger.

This suggests that maintenance may involve both:

Reinforcement.
Thoughts about threat and safety.

A complete two-process example

Scenario

When Ana was young, she became trapped in a lift during a power cut.

She was frightened and believed she would not escape.

Ana now avoids lifts and always uses stairs.

Process one: acquisition

Before the incident:

The lift was a neutral stimulus.
Being trapped and unable to escape was an unconditioned stimulus.
Fear was the unconditioned response.

During the incident:

Lift + frightening experience of being trapped → fear

After conditioning:

The lift became a conditioned stimulus.
Fear of lifts became a conditioned response.

Process two: maintenance

When Ana sees a lift:

She feels anxious.
She uses the stairs.
Anxiety decreases.
The relief negatively reinforces using the stairs.
Future avoidance becomes more likely.

Because Ana never enters a working lift, she does not learn that most lift journeys are safe.

How to apply the model to a scenario

Step 1: identify the frightening event

Look for:

Pain.
Injury.
Shock.
Being trapped.
A frightening noise.
A perceived threat.

This usually provides the unconditioned stimulus.

Step 2: identify the natural fear

The unconditioned stimulus naturally produces fear or distress.

This is the unconditioned response.

Step 3: identify the previously neutral object

This is the object or situation present during the frightening event.

It begins as the neutral stimulus.

Step 4: explain the association

State that the neutral stimulus and frightening event occurred together.

Step 5: identify the conditioned fear

The previously neutral stimulus becomes the conditioned stimulus and produces fear as the conditioned response.

Step 6: identify generalisation

Look for evidence that fear has spread to similar objects or situations.

Step 7: identify avoidance

State exactly what the person does to escape or prevent contact.

Step 8: explain negative reinforcement

Explain that avoidance removes anxiety.

The relief reinforces avoidance and makes it more likely to happen again.

An application table

Question to ask	Relevant concept
What was harmless before the event?	Neutral stimulus
What naturally caused fear?	Unconditioned stimulus
What was the natural fear response?	Unconditioned response
What stimulus now produces fear?	Conditioned stimulus
What is the learned response?	Conditioned response
Has the fear spread?	Stimulus generalisation
What does the person now avoid?	Avoidance behaviour
What consequence follows avoidance?	Relief from anxiety
Why does avoidance continue?	Negative reinforcement

Application example: fear of needles

A child receives a painful injection.

Later, the child becomes afraid whenever a needle is seen and avoids medical appointments.

Acquisition

Needle before the experience: neutral stimulus.
Pain from the injection: unconditioned stimulus.
Fear caused by pain: unconditioned response.
Needle after association: conditioned stimulus.
Fear of the needle: conditioned response.

Maintenance

Seeing a medical appointment causes anxiety.
The child refuses to attend.
Anxiety decreases.
Relief negatively reinforces avoidance.
Future medical appointments are more likely to be avoided.

Generalisation

The fear may spread to:

Doctors.
Hospitals.
Medical equipment.
Photographs of needles.
Other medical procedures.

Application example: fear of driving

A person is injured in a car accident.

Afterwards, they become anxious in any vehicle and refuse to drive.

Classical conditioning

Cars were initially neutral.
The accident, injury and shock were the unconditioned stimulus.
Fear was the unconditioned response.
Cars became conditioned stimuli.
Fear while travelling became the conditioned response.

Generalisation

The fear may spread from:

The particular road.
To all roads.
From driving.
To travelling as a passenger.

Operant conditioning

Refusing to drive reduces anxiety.

This relief negatively reinforces the refusal.

The person does not experience safe journeys that might weaken the fear.

Strengths of the two-process model

Strength: it clearly separates acquisition and maintenance

The model recognises that the reason a phobia begins may differ from the reason it continues.

A frightening experience may create the initial association.

Later, avoidance may maintain the fear even when the original danger is no longer present.

This is more complete than an explanation using classical conditioning alone.

Strength: evidence supports conditioned fear

Watson and Rayner’s Little Albert study demonstrated that:

Fear can be learned through association.
A neutral stimulus can become a conditioned stimulus.
Learned fear can generalise.

This supports the acquisition stage.

However, it does not prove that all naturally occurring phobias develop through classical conditioning.

Strength: real-life accounts sometimes identify trauma

Some people with phobias can identify an event that preceded the fear.

Examples include:

A dog attack before a dog phobia.
A frightening flight before a fear of flying.
Becoming trapped before claustrophobia.
A painful procedure before a needle phobia.

These experiences fit the classical-conditioning sequence.

Strength: avoidance produces observable relief

People with phobias often report that escaping or avoiding the feared stimulus reduces anxiety.

This consequence provides a plausible mechanism for maintenance.

The person repeatedly chooses the response that produces immediate relief, even when it creates long-term restrictions.

Strength: successful treatments are based on learning principles

Treatments derived from behavioural principles can reduce phobic fear.

Gradual counterconditioning treatment uses relaxation and gradual exposure.

Prolonged exposure treatment presents the feared stimulus without the expected harmful outcome.

These treatments aim to weaken the learned association and prevent avoidance.

Their effectiveness provides indirect support for the idea that learning processes are involved.

However:

A successful treatment does not prove that the disorder was originally caused by the same process.

A phobia could respond to exposure even if it developed through another route.

Strength: the model has practical applications

The explanation identifies avoidance as a target for treatment.

Instead of only discussing the original trauma, therapy can help the person:

Approach the feared stimulus.
Remain in the situation.
Discover that the feared outcome does not occur.
Learn that anxiety can decrease without escape.
Reduce dependence on safety behaviours.

This practical usefulness increases the model’s value.

Limitations of the two-process model

Limitation: not all phobias follow trauma

Many people with phobias cannot identify a frightening conditioning event.

For example, somebody may fear:

Snakes.
Spiders.
Heights.

without remembering any traumatic encounter involving them.

This challenges the claim that phobias are always acquired through direct classical conditioning.

Limitation: trauma does not always produce a phobia

Many people experience frightening events but do not develop lasting phobias.

For example:

Not everyone bitten by a dog develops a dog phobia.
Not everyone involved in an accident develops a fear of travel.
Not everyone trapped briefly in a lift develops claustrophobia.

The model does not fully explain these individual differences.

DiNardo and colleagues

DiNardo and colleagues investigated experiences involving dogs.

Unpleasant experiences with dogs were not limited to people with dog phobias.

People without a phobia had also experienced threatening or painful encounters.

This suggests that a traumatic event is neither:

Necessary for every phobia.
Sufficient to produce a phobia in every person.

Additional factors must influence whether fear develops.

Limitation: biological preparedness

Seligman proposed that humans are biologically prepared to learn some fears more readily than others.

Fears of ancestral dangers may be acquired particularly quickly.

Examples include:

Snakes.
Spiders.
Heights.
Enclosed spaces.

From an evolutionary perspective, rapidly learning to avoid genuine ancestral threats could have increased survival.

Prepared fears

A prepared fear is a fear that humans may be biologically ready to learn.

This does not mean that the fear is present from birth in a complete form.

It means that an association involving certain stimuli may be learned more easily and resist extinction.

The problem of modern dangers

Modern dangers such as:

Electrical sockets.
Cars.
Firearms.

may cause more actual harm than spiders in many environments.

Yet fears of ancestral threats remain common.

This pattern is difficult to explain through experience alone.

Behavioural equipotentiality

A simple conditioning account may imply equipotentiality, the assumption that any neutral stimulus can become associated with fear equally easily.

Preparedness challenges this assumption.

Some associations may be learned more readily because of evolutionary history.

Balanced interpretation of preparedness

Preparedness does not make learning irrelevant.

A more complete account may be:

Biological preparedness makes particular fears easier to acquire, while experience determines whether and how the fear develops.

Limitation: the model ignores cognitive factors

The two-process model focuses on associations and observable behaviour.

It gives less attention to thoughts such as:

“The dog will attack.”
“I will lose control.”
“The lift will become trapped.”
“I cannot cope.”
“The aircraft will crash.”

The irrational beliefs and distorted perceptions associated with phobias may influence both acquisition and maintenance.

Interpretation of the event

Two people may experience the same event but interpret it differently.

After a dog runs towards them:

One person may think the dog was excited.
Another may believe the dog intended to attack.

The second interpretation may make a phobia more likely.

The simple conditioning sequence does not fully explain this difference.

Expectations may maintain fear

A person may avoid a situation because they predict:

Injury.
Humiliation.
Panic.
Loss of control.
Inability to escape.

Avoidance may therefore be influenced by beliefs about safety, not only the automatic relief predicted by operant conditioning.

Limitation: avoidance may have different motivations

The model assumes avoidance continues because it reduces anxiety.

However, a person may also avoid because they believe the behaviour prevents real danger.

For example:

“The dog did not attack because I crossed the road.”

The person may attribute safety to avoidance.

This cognitive interpretation helps explain why the behaviour continues.

Limitation: phobias may be learned indirectly

A phobia may develop without direct contact with a frightening event.

Fear can also be acquired through:

Observing another person’s fear.
Hearing frightening information.
Repeated warnings.
Media reports.
Family responses.

For example, a child may observe a parent reacting fearfully to spiders and begin copying the response.

The two-process model’s direct classical-conditioning account does not fully explain this form of learning.

Limitation: not every phobia involves obvious avoidance

Some people remain in feared situations because avoidance is impossible or because the activity is important.

They may display endurance, remaining in the situation with severe distress.

For example, a person with a fear of flying may still travel for work.

The person’s fear may continue even without complete avoidance.

The operant component may therefore explain some cases more effectively than others.

Limitation: reductionism

The model is environmentally reductionist because it explains a complex disorder through two learning processes.

This produces a clear, testable account.

However, it may overlook interactions between:

Learning.
Cognition.
Biology.
Temperament.
Social experience.
Culture.

A more complete explanation may need several levels of analysis.

Limitation: environmental determinism

The model may appear environmentally deterministic because behaviour is presented as the result of conditioning and reinforcement.

This can underestimate:

Personal interpretation.
Conscious coping.
Individual choice.
Biological vulnerability.
Resistance to conditioning.

However, deterministic explanations can still be useful because they identify processes that can be changed through treatment.

Does treatment evidence prove the model?

Behavioural treatments provide important evidence, but the conclusion must remain cautious.

What treatment evidence shows

Successful exposure-based treatment suggests that:

Avoidance is important.
Safe exposure can weaken fear.
Learning processes influence phobic responses.
New associations can replace or compete with old learning.

What treatment evidence does not show

Treatment success does not establish:

That a traumatic conditioning event originally caused the phobia.
That cognition played no role.
That biological preparedness is irrelevant.
That all phobias develop through the same route.

The evidence supports behavioural involvement without proving a complete behavioural cause.

Evaluating research evidence effectively

Weak research evaluation

Little Albert was unethical.

This does not explain what the ethical problem means for the model.

Stronger research evaluation

Watson and Rayner demonstrated that a neutral stimulus could acquire a fear response through association, supporting classical conditioning. However, the evidence came from one child in a controlled situation, so it cannot establish that the same process explains all naturally occurring phobias.

Weak counterevidence

DiNardo disagrees with the model.

This does not explain the finding or implication.

Stronger counterevidence

DiNardo and colleagues found that unpleasant experiences with dogs were also reported by people who had not developed dog phobias. A traumatic association is therefore not sufficient by itself, suggesting that individual, cognitive or biological factors affect whether conditioning produces a phobia.

Applying evaluation to the two stages

Acquisition evaluation

Relevant issues include:

Evidence that fears can be conditioned.
Lack of remembered trauma in many cases.
Trauma without later phobia.
Preparedness.
Indirect learning.
Cognitive interpretation.

Maintenance evaluation

Relevant issues include:

Relief following avoidance.
Avoidance preventing extinction.
Safety behaviours.
Endurance rather than avoidance.
Cognitive expectations of danger.
Success of exposure treatments.

Organising evaluation around the two stages helps keep the answer focused.

A balanced assessment

The two-process model provides a clear account of how phobias can be learned and maintained.

Its strongest contributions are:

Explaining the role of traumatic association.
Distinguishing acquisition from maintenance.
Explaining why avoidance persists.
Supporting effective behavioural treatments.

However, it cannot explain every case because:

Some phobias develop without direct trauma.
Trauma does not always produce a phobia.
Some fears are biologically prepared.
Thoughts and interpretations influence fear.
Fear can be acquired indirectly.
Some people endure feared situations rather than avoid them.

The most justified conclusion is:

Classical and operant conditioning provide important mechanisms within phobias, but they are more convincing as part of a broader explanation that also includes biological, cognitive and social factors.

Planning an extended response

A strong discussion could follow this structure:

Define the two-process model.
Explain acquisition through classical conditioning.
Define NS, UCS, UCR, CS and CR.
Explain stimulus generalisation.
Explain maintenance through operant conditioning.
Explain negative reinforcement.
Explain how avoidance prevents extinction.
Apply both processes to the scenario.
Use Little Albert as supporting evidence.
Explain why trauma is not always necessary or sufficient.
Discuss biological preparedness.
Discuss neglected cognitive or social factors.
Use behavioural treatments as practical support.
Reach a balanced conclusion.

Hints from the Examiner Reports 💡

Examiner hint: Always include both processes. In the June 2024 application question, answers needed classical conditioning and operant conditioning applied to the scenario. Applying only one part of the model was capped at half marks.

Examiner hint: Apply every technical term. Identify the specific neutral stimulus, unconditioned stimulus, unconditioned response, conditioned stimulus and conditioned response from the scenario.

Examiner hint: The frightening event is normally the unconditioned stimulus. Fear is the unconditioned response, not the stimulus.

Examiner hint: State that the previously neutral phobic object becomes a conditioned stimulus through association.

Examiner hint: When explaining maintenance, use the complete negative-reinforcement sequence: avoidance removes anxiety, the resulting relief reinforces avoidance, and avoidance becomes more likely.

Examiner hint: Do not describe negative reinforcement as punishment. Reinforcement increases avoidance behaviour.

Examiner hint: Generalisation can earn valuable application credit when the scenario shows fear spreading to similar objects or situations.

Why this loses focus:

The question concerns the explanation rather than treatment.

How to improve:

Use treatment effectiveness briefly as indirect support for behavioural principles.

Exam-Style Questions ✍️

Question 1

Which one of the following correctly identifies the two processes in the two-process model?

A. Classical conditioning acquires the phobia and operant conditioning maintains it

B. Operant conditioning acquires the phobia and classical conditioning maintains it

C. Classical conditioning acquires and maintains the phobia

D. Operant conditioning acquires and maintains the phobia

[1 mark]

reveal mark scheme and indicative content

Answer: A. Classical conditioning acquires the phobia and operant conditioning maintains it

Question 2

Define negative reinforcement in the context of phobias.

[2 marks]

reveal mark scheme and indicative content

Mark scheme

AO1 = 2

2 marks: Clear definition referring to a behaviour becoming more likely because it removes or reduces an unpleasant experience, applied to fear or anxiety.
1 mark: Limited or partial definition.

Indicative content

Avoidance removes or reduces fear/anxiety.
This relief acts as a reinforcer.
Avoidance therefore becomes more likely to occur again.

Example answer

Negative reinforcement occurs when avoiding a phobic stimulus reduces anxiety, making the person more likely to use avoidance again in the future.

AQA specifically credits the relief produced by avoidance as negatively reinforcing phobic behaviour.

Question 3

Explain how a phobia may be acquired through classical conditioning.

[4 marks]

reveal mark scheme and indicative content

Mark scheme

AO1 = 4

Award 1 mark for each relevant point, up to 4 marks.

Indicative content

A previously neutral stimulus is encountered alongside a frightening or painful unconditioned stimulus (UCS).
The UCS naturally produces fear, the unconditioned response (UCR).
Through association, the neutral stimulus becomes a conditioned stimulus (CS).
The CS then produces fear on its own, a conditioned response (CR).
The result may be a phobia of the previously neutral stimulus.

Example answer

A neutral stimulus may become associated with a frightening unconditioned stimulus that naturally produces fear. After repeated pairing, or sometimes a single traumatic pairing, the neutral stimulus becomes a conditioned stimulus. It can then produce fear as a conditioned response even when the original frightening event is absent.Question 4

Question 4

Explain the role of stimulus generalisation in phobias.

[3 marks]

reveal mark scheme and indicative content

Mark scheme

AO1 = 3

Award 1 mark each for:

Fear is initially conditioned to a particular stimulus.
The fear response may then spread to similar stimuli.
As a result, the phobia may become broader than the object or situation involved in the original conditioning experience.

AQA explicitly credits the generalisation of fear to similar objects or situations within the two-process model.

Example answer

Stimulus generalisation occurs when a conditioned fear spreads from the original conditioned stimulus to similar stimuli. For example, someone bitten by one dog may begin to fear many different dogs, even though the other dogs were not involved in the original frightening event.

Question 5

Following a painful dog bite, Sofia becomes frightened of all dogs. She now takes a longer route to college to avoid a park where dogs are walked.

Use the two-process model to explain Sofia’s behaviour.

[6 marks]

reveal mark scheme and indicative content

Mark scheme

AO2 = 6

Award credit for effective application of both processes.

Classical conditioning

The painful bite is an unconditioned stimulus producing fear.
The dog becomes associated with the pain and becomes a conditioned stimulus.
Fear generalises from the original dog to all dogs.

Operant conditioning

Sofia avoids the park by taking a longer route.
Avoidance reduces her fear or anxiety.
This relief negatively reinforces taking the alternative route, maintaining the phobia.

For AQA's comparable 2024 six-mark application question, answers needed both classical and operant conditioning for full marks.

Example answer

Sofia's phobia may have been acquired through classical conditioning. The painful dog bite naturally produced fear, and the dog became associated with this fear. The conditioned fear then generalised to other dogs, explaining why she is now frightened of all dogs. Her phobia is maintained through operant conditioning. Taking a longer route means she avoids dogs and experiences relief from anxiety. This relief negatively reinforces her avoidance, making her more likely to continue avoiding dogs.

Question 6

A child becomes trapped in a lift during a power cut. The child later refuses to enter any lift and feels relieved whenever stairs are available.

Explain the acquisition and maintenance of the child’s fear.

[6 marks]

reveal mark scheme and indicative content

Mark scheme

AO2 = 6

Award up to 3 marks for acquisition and 3 marks for maintenance.

Indicative content

Acquisition

Being trapped during the power cut is a frightening experience.
The lift becomes associated with fear through classical conditioning.
The lift can subsequently produce fear even when it is operating normally.

Maintenance

The child avoids lifts by using stairs.
Using the stairs reduces the child's fear and produces relief.
This relief negatively reinforces lift avoidance, maintaining the phobia.

Example answer

The fear may be acquired through classical conditioning. Being trapped in the lift is frightening, so the lift becomes associated with fear and later produces a conditioned fear response. The fear is then maintained through operant conditioning. Using the stairs allows the child to avoid the lift and produces relief from anxiety. This relief negatively reinforces avoidance, making the child more likely to continue using the stairs.

Question 7

Explain one difference between the role of classical conditioning and the role of operant conditioning in the two-process model.

[4 marks]

reveal mark scheme and indicative content

Mark scheme

AO1 = 4

Award credit for a clear, developed distinction.

Indicative content

Classical conditioning explains the acquisition of a phobia.
It involves forming an association between a previously neutral stimulus and a frightening experience.
Operant conditioning explains the maintenance of a phobia.
Avoidance is negatively reinforced because it reduces anxiety.

Example answer

Classical conditioning explains how the phobia initially develops because a neutral stimulus becomes associated with fear. Operant conditioning explains why the phobia continues because avoiding the feared stimulus reduces anxiety. This relief negatively reinforces avoidance, so the person continues to avoid the stimulus.

Question 8

A researcher finds that many people who experienced frightening encounters with dogs did not develop dog phobias.

Explain one limitation of the two-process model illustrated by this finding.

[4 marks]

reveal mark scheme and indicative content

Mark scheme

AO3 = 4

Award credit for one clearly developed limitation.

Indicative content

The two-process model predicts that frightening experiences can condition phobic responses.
However, many people who experience traumatic events do not develop phobias.
This suggests that conditioning alone is insufficient to explain who develops a phobia.
Other factors, such as biological preparedness, individual vulnerability or cognitive processes, may also be involved.
Therefore, the model may be an incomplete explanation.

AQA explicitly credits the criticism that not all phobias result from trauma and accepts alternative evolutionary explanations such as preparedness.

Example answer

This finding suggests that classical conditioning alone cannot fully explain the acquisition of phobias. If frightening experiences automatically produced conditioned phobias, most people who had frightening encounters with dogs should develop a dog phobia. Because many do not, other factors such as biological preparedness or individual vulnerability may also influence whether a phobia develops.

Question 9

Explain one way in which the effectiveness of exposure-based treatments may support the two-process model.

[4 marks]

reveal mark scheme and indicative content

Mark scheme

AO3 = 4

Award 1 mark each for:

The two-process model proposes that phobias are maintained because avoidance is negatively reinforced.
Exposure-based therapies require the person to encounter the feared stimulus rather than avoid it.
Without avoidance, the person cannot obtain the usual reinforcing relief by escaping.
If anxiety eventually decreases and the phobia improves, this supports the importance of conditioning and avoidance in maintaining phobias.

Indicative content

Successful treatments based on behavioural principles provide support for the explanation because changing learned avoidance behaviour can reduce the phobia.

AQA explicitly accepts the fact that behavioural principles underpin effective treatments, including exposure and counterconditioning, as support for the two-process model.

Example answer

Exposure-based treatments support the two-process model because they prevent avoidance. The model argues that avoidance maintains a phobia because escaping the feared stimulus reduces anxiety and is negatively reinforcing. During exposure, the person remains with the feared stimulus instead. If their anxiety eventually falls and the phobia improves, this supports the idea that learned avoidance plays an important role in maintaining phobias.

Question 10

Discuss the two-process model of phobias. Refer to an unfamiliar phobia in your answer.

[16 marks]

reveal mark scheme and indicative content