Harlow’s animal study of attachment | AQA A-Level Psychology Revision
Updated: Sep 9
For 7182 specification, first teach in September 2025
AQA A-Level Psychology | Free Revision Notes
Estimated study time: 40 minutes
These Harlow’s animal study of attachment A-Level Psychology revision notes examine whether infant attachment is based mainly on feeding or physical comfort. Harlow offered infant rhesus monkeys a wire surrogate mother and a soft cloth surrogate mother. The monkeys strongly preferred the cloth mother, even when the wire mother provided food. The research demonstrates the importance of contact comfort and suggests that disrupted early relationships can have lasting effects. Harlow is one of the two animal studies named in the AQA attachment specification.
Learning Objectives 🎯
By the end of this revision page, you should be able to:
Describe Harlow’s research using infant rhesus monkeys.
Explain the importance of contact comfort.
Explain how Harlow’s findings challenge a feeding-based account of attachment.
Describe the effects of disrupted early relationships on later behaviour.
Evaluate the scientific strengths and limitations of the research.
Evaluate the ethical issues raised by Harlow’s procedures.
These objectives follow the planned focus on Harlow’s research, contact comfort and the scientific and ethical issues created by animal attachment studies.
Revision Notes 📚
Harlow’s animal study of attachment overview
Harry Harlow investigated attachment using infant rhesus monkeys.
At the time, some explanations suggested that infants become attached to a caregiver because the caregiver provides food.
Harlow tested whether attachment depended more strongly on:
Feeding.
Physical softness.
Warmth and comfort.
A sense of security.
He did this by giving infant monkeys access to two artificial or surrogate mothers.
One surrogate was made from bare wire.
The other was covered in soft cloth.
Harlow then observed which mother the monkeys preferred and how they behaved when frightened.
Why did Harlow use rhesus monkeys?
Rhesus monkeys are mammals with relatively complex social behaviour.
Like human infants, young monkeys:
Depend on adult care.
Seek physical contact.
Form close social relationships.
Show distress when separated.
Develop through interaction with other members of their species.
This may make monkeys more relevant to human attachment than the birds used in research into imprinting.
However, rhesus monkeys and humans remain different species. Similarity does not mean that findings can be transferred directly.
The aim of Harlow’s research
Harlow aimed to investigate whether infant monkeys would form a stronger attachment to:
A surrogate mother that provided food.
Or a surrogate mother that provided contact comfort.
He also investigated whether early experiences with surrogate caregivers affected:
Exploration.
Responses to fear.
Social development.
Later relationships.
Parenting behaviour.
What is a surrogate mother?
A surrogate mother is a substitute caregiver.
In Harlow’s study, the surrogate mothers were artificial structures rather than living monkeys.
The two surrogates differed in their physical properties:
Wire mother | Cloth mother |
Made from uncovered wire | Covered in soft material |
Hard and uncomfortable | Soft and physically comforting |
Could be fitted with a feeding bottle | Could also be fitted with a feeding bottle |
Provided little contact comfort | Provided substantial contact comfort |
The use of two contrasting surrogates allowed Harlow to compare the effects of food and comfort.
The procedure
Separation from the biological mother
Infant rhesus monkeys were separated from their biological mothers soon after birth.
They were raised with access to two surrogate mothers:
One made from wire.
One covered in soft cloth.
This meant that the infants did not receive normal maternal care from an adult monkey.
Manipulating the source of food
For some monkeys:
The wire mother provided milk.
The cloth mother provided no milk.
For other monkeys:
The cloth mother provided milk.
The wire mother provided no milk.
This was an important part of the procedure.
It allowed Harlow to investigate whether the monkeys preferred the mother associated with food or the mother associated with physical comfort.
Measuring preference
Harlow recorded how much time the infant monkeys spent with each surrogate mother.
If feeding were the main basis of attachment, the monkeys should have spent most of their time with whichever mother provided milk.
If contact comfort were more important, the monkeys should have preferred the cloth mother regardless of which surrogate provided food.
Fear response
Harlow also observed how the monkeys responded to frightening or unfamiliar objects.
For example, a monkey might be exposed to a mechanical object designed to produce fear.
Harlow recorded whether the monkey:
Approached the wire mother.
Approached the cloth mother.
Attempted to escape.
Froze.
Clung to one of the surrogates.
This helped test which mother provided emotional security.
Exploration of a new environment
The monkeys were also observed in unfamiliar surroundings.
Harlow examined whether the presence of the cloth mother affected:
Exploration.
Confidence.
Fear.
Willingness to move away from the surrogate.
Returning to the surrogate after encountering something unfamiliar.
This allowed the cloth mother’s role as a possible secure base to be investigated.
The findings
Preference for the cloth mother
The infant monkeys spent considerably more time clinging to the cloth mother than to the wire mother.
This preference occurred even when the wire mother provided milk.
The monkeys usually approached the wire mother only to feed before returning to the cloth mother.
The basic pattern was:
Wire mother provides milk → monkey feeds → monkey returns to cloth mother
This finding suggests that feeding alone did not explain the attachment.
Response when frightened
When frightened, the monkeys usually sought the cloth mother.
They clung to the soft surrogate rather than approaching the wire mother.
This suggests that the cloth mother provided:
Reassurance.
Security.
Protection.
Contact comfort.
The feeding mother did not necessarily become the preferred source of safety.
Exploration
The cloth mother appeared to provide a secure base.
When the cloth mother was present, monkeys were more willing to:
Explore an unfamiliar environment.
Move away from the surrogate.
Investigate objects.
Return to the surrogate when frightened.
Without the cloth mother, the monkeys showed greater fear and were less confident in exploring.
Central conclusion
Harlow concluded that contact comfort was more important than feeding in the formation of attachment.
The monkeys formed their strongest attachment to the soft surrogate, even when it did not provide food.
The research therefore challenged a simple version of the feeding and reinforcement explanation of attachment.
Summary of the main findings
Observation | What it suggests |
Monkeys spent most time with the cloth mother | Soft physical contact was strongly preferred |
Preference remained when the wire mother provided milk | Feeding was not the main basis of attachment |
Frightened monkeys ran to the cloth mother | Contact comfort provided security |
Monkeys explored more with the cloth mother present | The cloth surrogate acted as a secure base |
Abnormal early care affected later behaviour | Early relationships may influence later development |
What is contact comfort?
Contact comfort is the physical and emotional reassurance provided by close, soft bodily contact with a caregiver.
It may involve:
Clinging.
Cuddling.
Warmth.
Softness.
Physical closeness.
Reassurance during fear.
Contact comfort is not the same as food.
A caregiver can provide food without providing comforting physical contact.
Harlow’s monkeys demonstrated this distinction by feeding from the wire mother but spending most of their remaining time with the cloth mother.
Contact comfort and emotional security
The cloth mother did more than provide a pleasant surface.
The monkeys used it as a source of security.
When frightened, they did not simply approach the nearest object or the mother associated with food. They sought the soft surrogate.
This suggests that contact comfort may contribute to attachment by reducing distress.
The process can be represented as:
Infant experiences fear → seeks physical contact → distress is reduced → caregiver becomes a source of security
Contact comfort and the secure base
A secure base is a caregiver from whom an infant can explore and to whom the infant can return for reassurance.
The cloth mother appeared to perform this function.
When it was available, the monkey could:
Move away and explore.
Encounter something unfamiliar.
Return to the cloth mother.
Gain reassurance.
Resume exploration.
The monkey’s dependence on contact comfort did not prevent exploration. Instead, security appeared to support it.
Contact comfort versus feeding
Harlow’s study can be understood as a comparison between two possible explanations.
Feeding-based explanation
The infant becomes attached to the person who supplies food.
The caregiver gains value because they satisfy hunger.
Contact-comfort explanation
The infant seeks softness, warmth and security independently of feeding.
Food may be important for survival, but it does not fully explain the emotional bond.
Harlow’s findings supported the second explanation.
Why the feeding result matters
The study did not simply show that monkeys like soft materials.
It separated comfort from feeding.
The crucial finding was that the monkeys preferred the cloth mother even when:
The wire mother provided milk.
The cloth mother did not provide milk.
This made it difficult to explain the preference through food reinforcement alone.
Applying contact comfort
Example involving two caregivers
An infant monkey is fed by a hard wire surrogate but spends most of the day clinging to a soft surrogate that provides no food.
Harlow’s findings would explain this because:
The wire surrogate satisfies hunger.
The cloth surrogate provides contact comfort.
Contact comfort is more important for the attachment preference.
The monkey therefore returns to the cloth surrogate after feeding.
Example involving fear
An infant monkey is shown a noisy mechanical object.
It immediately runs to the cloth surrogate and clings to it.
This supports contact comfort because the soft surrogate is being used as a source of emotional security rather than nutrition.
Example involving exploration
A monkey explores a new enclosure while the cloth surrogate is present but freezes when the surrogate is removed.
This suggests that the cloth mother acts as a secure base.
Its presence reduces fear and allows exploration.
Four-stage application structure
Use this structure in an examination:
Identify the relevant surrogate.
State whether it provides food or comfort.
Describe the monkey’s behaviour.
Link the behaviour to contact comfort or security.
Weak application
The monkey likes the cloth mother because of Harlow.
Stronger application
The monkey spends most of its time clinging to the cloth surrogate, even though the wire surrogate provides milk. This supports Harlow’s conclusion that contact comfort is more important than feeding in determining attachment behaviour.
Long-term effects of disrupted early attachment
Abnormal social development
The monkeys raised without normal maternal care later showed disturbed social behaviour.
Some appeared:
Less sociable.
More fearful.
More aggressive.
Unable to interact normally with other monkeys.
Uncertain about how to form social relationships.
This suggests that physical comfort from an artificial surrogate was not enough to produce completely normal development.
The monkeys also required ordinary interaction with living members of their species.
Difficulties with mating
Some monkeys had difficulty forming normal sexual relationships as adults.
They could struggle to:
Interact appropriately with potential mates.
Recognise normal social signals.
Participate in mating behaviour.
This indicates that disrupted early social experience may affect later relationships.
It provides indirect animal evidence relevant to the association between early attachment and later relationships.
Difficulties with parenting
Some female monkeys that later became mothers showed abnormal parenting behaviour.
They might:
Neglect their infants.
Reject physical contact.
Behave aggressively towards their offspring.
Fail to provide ordinary maternal care.
This suggests possible continuity between early caregiving experiences and later caregiving behaviour.
However, it would be too strong to conclude that every human who experiences disrupted attachment will become an inadequate parent.
Duration of deprivation
Harlow’s work suggested that the severity of later difficulties was related to the length of early social deprivation.
Longer deprivation was associated with:
More severe behavioural difficulties.
Greater problems forming relationships.
Less complete recovery.
This supports the idea that early experiences may have particularly significant developmental effects.
It can be linked cautiously to the possible consequences of prolonged separation from a caregiver.
Evidence of some recovery
Later work found that some socially deprived monkeys could improve when they interacted with younger, socially skilled monkeys.
These younger companions have sometimes been described as monkey therapists.
The deprived monkeys could gradually become:
More sociable.
Less fearful.
Better able to interact.
This suggests that early damage was not always completely irreversible.
The finding is important because it shows that:
Early experience matters.
Later social support can also matter.
Development may retain some flexibility.
What does Harlow’s research suggest about human
attachment?
Attachment involves more than food
The strongest implication is that infants may not become attached simply because a caregiver feeds them.
Human caregivers also provide:
Comfort.
Physical closeness.
Protection.
Emotional responsiveness.
Reassurance.
Harlow’s findings therefore challenge a purely feeding-based explanation of human attachment.
Early relationships may support later development
The later difficulties shown by deprived monkeys suggest that early relationships may contribute to:
Social development.
Emotional regulation.
Relationship formation.
Parenting behaviour.
This is broadly consistent with Bowlby’s account of early attachment as biologically important.
However, Harlow’s study cannot establish that humans experience exactly the same outcomes.
A caregiver can provide security
The cloth mother appeared to operate as a secure base.
Human infants may also use an attachment figure as a source of security from which to explore.
This idea later became important in the assessment of attachment behaviour.
Comfort alone may not be sufficient
The monkeys preferred the cloth mother, but those raised without normal social care still developed behavioural difficulties.
This suggests that attachment requires more than a soft or physically comforting object.
Normal development may also depend on:
Responsive interaction.
Communication.
Social play.
Reciprocal behaviour.
Relationships with other members of the species.
Harlow’s findings therefore show the importance of comfort while also showing its limits.
Scientific strengths
High control
Harlow’s study was conducted under controlled conditions.
The researcher could control:
The material covering each surrogate.
Which surrogate provided milk.
The monkeys’ access to each mother.
The frightening object used.
The observation conditions.
The unfamiliar environment.
This allowed the effects of feeding and contact comfort to be separated.
Cause and effect
Because the source of milk was manipulated, Harlow could examine whether feeding caused the attachment preference.
The monkeys preferred the cloth mother regardless of which surrogate provided milk.
This supports a causal conclusion:
Soft contact, rather than food provision alone, influenced the monkeys’ attachment behaviour.
Objective behavioural measures
The study used observable measures, including:
Time spent with each surrogate.
Which surrogate was approached.
Behaviour when frightened.
Exploration of the environment.
These measures are more objective than relying on the researcher’s impression that a monkey “loved” one mother.
Replicability
The use of standardised surrogate mothers and controlled procedures made the research potentially replicable.
Another researcher could:
Provide the same two surrogates.
Manipulate the feeding source.
Measure contact time.
Observe fear responses.
Replicability is a scientific strength because findings can be checked.
Long-term observation
Harlow examined behaviour beyond the immediate attachment preference.
He observed later:
Social interaction.
Mating behaviour.
Parenting.
Recovery.
This allowed the research to investigate possible developmental consequences rather than only short-term clinging.
Rhesus monkeys share relevant characteristics with humans
Rhesus monkeys are social mammals.
They share more relevant biological and social characteristics with humans than goslings do.
For example, both human and rhesus infants:
Require prolonged care.
Seek physical contact.
Develop through social interaction.
Form complex relationships.
This may increase the possible relevance of Harlow’s research to humans.
Scientific limitations
Artificial surrogate mothers
A wire structure and a cloth-covered structure are not ordinary monkey caregivers.
A living mother would provide:
Movement.
Warmth.
Feeding.
Grooming.
Social responses.
Protection.
Communication.
The artificial setting isolated contact comfort, which increased control, but it may not represent natural attachment.
Extreme rearing conditions
The monkeys experienced conditions far removed from ordinary development.
Most human infants are not raised with a choice between:
A feeding wire structure.
A non-feeding cloth structure.
This limits ecological validity.
The findings demonstrate the importance of comfort under these conditions, but attachment in a normal family is more complex.
Generalising from monkeys to humans
Humans and rhesus monkeys share some characteristics, but there are still major species differences.
Human attachment is influenced by:
Language.
Culture.
Conscious beliefs.
Several caregivers.
Social expectations.
Complex emotional communication.
Monkey behaviour cannot provide direct proof about human relationships.
Attachment was measured through behaviour
Harlow measured behaviours such as clinging and approaching.
These are reasonable indicators of attachment, but they do not reveal the animal’s exact emotional experience.
The monkey may approach the cloth mother because it:
Feels secure.
Prefers the texture.
Has learned that contact reduces fear.
Has no more suitable social figure available.
Researchers must infer the internal attachment from outward behaviour.
Limited population
Research using a particular species under highly controlled conditions may not generalise to:
Other monkey species.
Other mammals.
Humans.
Infants raised in ordinary social groups.
The findings provide a useful principle but should not be treated as universal.
Difficulty separating several effects
The monkeys were deprived of more than their biological mother.
They also lacked:
Normal social interaction.
Ordinary maternal responses.
Typical peer relationships.
Natural rearing conditions.
Later difficulties cannot necessarily be attributed to the absence of one specific type of attachment.
The abnormal development may result from a combination of social deprivation and artificial rearing.
Ethical issues
Separation from the biological mother
The infant monkeys were deliberately separated from their mothers.
This prevented normal maternal care and created significant disruption during early development.
The animals could not consent to this separation.
Psychological distress
The monkeys showed signs of fear and distress.
The procedures deliberately created situations in which the infants:
Lacked a normal caregiver.
Encountered frightening objects.
Sought comfort from an artificial structure.
Experienced abnormal social conditions.
This raises concerns about protection from psychological harm.
Long-term harm
The ethical concerns are particularly serious because the effects were not limited to temporary discomfort.
Some monkeys later experienced:
Social difficulties.
Aggression.
Fear.
Problems mating.
Abnormal parenting behaviour.
The research therefore caused or contributed to enduring harm.
Inability to withdraw
The monkeys could not understand the research or communicate informed consent.
They could not exercise a meaningful right to withdraw from:
Maternal separation.
Artificial rearing.
Fear tests.
Long-term observation.
This places a strong responsibility on the researcher to minimise harm.
Was the harm justified?
Ethical evaluation requires a comparison between:
The harm caused.
The scientific and practical value of the findings.
Possible benefits
The research provided evidence that:
Feeding is not sufficient to explain attachment.
Physical comfort is important.
Early social deprivation can have long-term consequences.
Later social intervention may support recovery.
Ethical costs
The monkeys experienced:
Maternal separation.
Fear.
Abnormal development.
Long-term social and emotional difficulties.
A reasoned evaluation should recognise both sides before reaching a judgement.
Historical importance does not remove the harm
Harlow’s work had an important influence on attachment theory and childcare.
However, valuable findings do not automatically make every procedure ethically acceptable.
The same research question should be investigated using less harmful methods whenever possible.
Ethical alternatives
Some aspects of attachment can be studied through less harmful methods, including:
Observing naturally occurring caregiver behaviour.
Comparing animals reared under existing conditions.
Using non-invasive observation.
Studying naturally occurring separations.
Examining the effectiveness of supportive interventions.
These methods may provide less control, but they reduce deliberate harm.
Practical applications
Importance of emotional care
Harlow’s findings suggest that meeting an infant’s physical needs is not sufficient.
Providing food and shelter without emotional and physical comfort may not support healthy development.
Care should also include:
Warmth.
Responsiveness.
Reassurance.
Physical contact where appropriate.
Stable relationships.
Childcare institutions
The research contributed to awareness that children in institutional care require more than basic physical care.
Frequent changes of caregiver and limited emotional interaction may affect development.
This connects with the developmental effects of institutional care.
Hospital care
Extended separation from caregivers may be distressing for young children.
The findings support practices that allow:
Caregiver contact.
Comfort.
Familiarity.
Stable emotional support.
Adoption and fostering
Harlow’s research suggests that stable, responsive care should be established as early as possible.
However, evidence of recovery among some monkeys also cautions against assuming that early difficulties are always permanent.
Harlow and learning theory
How learning theory explains attachment
Learning theory proposes that attachment develops because a caregiver becomes associated with food.
Through conditioning:
Food produces pleasure.
The caregiver becomes associated with food.
The caregiver gains rewarding properties.
Attachment develops.
Why Harlow challenges learning theory
The monkeys preferred the cloth mother even when the wire mother provided food.
This suggests that:
Food provision did not determine the preferred attachment figure.
Contact comfort had an independent effect.
Attachment cannot be explained fully through hunger reduction.
The study therefore challenges the view that the person who feeds the infant must become the primary attachment figure.
Does Harlow completely disprove learning?
No.
The monkeys may still have learned that the cloth mother reduced fear.
Attachment behaviour can involve both:
Biologically important comfort.
Learning through repeated experiences.
The most justified conclusion is that food reinforcement alone is insufficient.
Comparing Harlow and Lorenz
Harlow | Lorenz |
Studied rhesus monkeys | Studied goslings |
Investigated contact comfort | Investigated imprinting |
Compared cloth and wire surrogates | Compared first exposure to mother or human |
Examined feeding versus comfort | Examined the first moving object encountered |
Found long-term social consequences | Found later sexual imprinting |
Mammalian model may be closer to humans | Bird behaviour differs substantially from human attachment |
Raised severe ethical concerns | Also interfered with natural maternal and mating behaviour |
Both studies suggest that:
Early social experiences are important.
Attachment-related behaviours may have a biological basis.
Early disruption can have lasting effects.
However, neither study provides direct proof about human attachment.
Evaluating Harlow in an examination
A scientific strength paragraph
Use this structure:
State the scientific feature.
Link it to the procedure.
Explain how it improves the conclusion.
For example:
Harlow used a highly controlled procedure in which the feeding bottle could be attached to either the wire or cloth surrogate. The monkeys preferred the cloth mother regardless of which surrogate provided milk. This allowed Harlow to separate feeding from comfort and supports a causal conclusion that contact comfort influenced attachment behaviour.
An ethical limitation paragraph
Use this structure:
Identify the harm.
Give study-specific evidence.
Consider the cost-benefit balance.
For example:
The monkeys experienced long-term psychological harm, including social and parenting difficulties. This harm went beyond temporary distress and could not be reversed easily. Although the research produced influential findings about contact comfort, the severity and duration of the damage make its ethical justification highly controversial.
A generalisability paragraph
Rhesus monkeys are social mammals and may provide a more relevant model of human attachment than birds. However, human attachment involves language, culture and more complex relationships. The findings therefore support broad principles about comfort and early care but cannot be transferred directly to human infants.
Hints from the Examiner Reports 💡
Examiner hint: Distinguish the procedure from the findings. If asked for findings, focus on the cloth-mother preference, fear response and later behavioural effects rather than describing how the cages were arranged.
Examiner hint: The strongest finding is not simply that the monkeys preferred cloth. They preferred the cloth mother regardless of which surrogate provided milk.
Examiner hint: Explain contact comfort rather than merely naming it. Link soft physical contact to security, fear reduction and the use of the cloth mother as a secure base.
Examiner hint: For a short findings question, select clear outcomes and avoid filling the answer with evaluation. AQA mark schemes credit the preference for the cloth mother, seeking it when frightened and the later effects of abnormal early care.
Examiner hint: When asked what Harlow’s research tells us about human attachment, make the link explicit. Explain the possible human implication and then consider species differences.
Examiner hint: Do not evaluate the study in isolation when the question asks about human attachment. AQA examiner commentary has noted that students often described Lorenz or Harlow accurately but failed to connect their evaluation to what the findings might tell us about humans.
Examiner hint: Ethical evaluation should identify specific harm, such as long-term social or parenting difficulties, rather than making the undeveloped statement that “animal research is unethical”.
Examiner hint: Scientific evaluation should consider both control and artificiality. Controlled surrogate mothers helped isolate contact comfort, but they did not represent normal caregiving.
Common Mistakes ⚠️
Mistake: Saying that the monkeys preferred the mother that provided food
Why this is incorrect:
The monkeys preferred the cloth mother even when the wire mother supplied milk.
How to improve:
State that contact comfort was more important than feeding in determining the preference.
Mistake: Saying that the cloth mother always provided milk
Why this is incorrect:
The source of milk was varied. In some conditions, the wire mother provided it.
How to improve:
Explain that the feeding arrangement allowed Harlow to separate food from comfort.
Mistake: Describing contact comfort as feeding
Why this is incorrect:
Contact comfort involves softness, physical closeness and reassurance.
How to improve:
Distinguish emotional security from hunger satisfaction.
Mistake: Saying that the monkeys never approached the wire mother
Why this is inaccurate:
Monkeys approached the wire mother when it supplied food but returned to the cloth mother afterwards.
How to improve:
Distinguish brief feeding contact from the preferred attachment figure.
Mistake: Ignoring the fear test
Why this matters:
The fear response provides evidence that the cloth mother offered security rather than only a pleasant texture.
How to improve:
Explain that frightened monkeys sought and clung to the cloth mother.
Mistake: Assuming the cloth mother produced normal development
Why this is incorrect:
The monkeys still lacked a living, responsive caregiver and normal social relationships.
How to improve:
Explain that contact comfort was important but not sufficient for healthy development.
Mistake: Saying that the study proves how human infants attach
Why this is incorrect:
Rhesus monkeys provide indirect evidence and humans have more complex social development.
How to improve:
Use cautious language such as “suggests” and “may help explain”.
Mistake: Saying that monkeys and humans are completely incomparable
Why this is too extreme:
Both are social mammals and may share relevant attachment processes.
How to improve:
Balance biological similarities against differences in language, culture and relationship complexity.
Mistake: Giving only a generic laboratory strength
Why this is incomplete:
The strength must be linked to Harlow’s specific procedure.
How to improve:
Explain how changing the source of food allowed contact comfort to be isolated.
Mistake: Saying only that the study was cruel
Why this is incomplete:
An ethical argument requires evidence and explanation.
How to improve:
Refer to maternal separation, fear and lasting social or parenting difficulties.
Mistake: Ignoring practical value
Why this matters:
Evaluation should consider the knowledge gained as well as the harm caused.
How to improve:
Explain how the research demonstrated the need for emotional care in addition to food and shelter.
Mistake: Confusing Harlow with Lorenz
Why this is incorrect:
Harlow investigated contact comfort in monkeys. Lorenz investigated imprinting in goslings.
How to improve:
Remember:
Harlow = cloth, wire and comfort.
Lorenz = first moving object and imprinting.
Exam-Style Questions ✍️
Question 1
Which one of the following best describes contact comfort?
A. Attachment formed because a caregiver provides food
B. Security gained from soft physical contact with a caregiver
C. Following the first moving object seen after birth
D. Learning attachment through punishment
[1 mark]
reveal the mark scheme and indicative content
Answer: B. Security gained from soft physical contact with a caregiver
Question 2
Define contact comfort.
[2 marks]
reveal the mark scheme and indicative content
Mark scheme
AO1 = 2
2 marks: Clear definition referring to comfort or security gained from soft physical contact with an attachment figure.
1 mark: Limited or partial definition.
Indicative content
Physical comfort provided by close contact.
Associated with softness, warmth and security.
Harlow's research suggested that this could be more important for attachment than food.
Example answer
Contact comfort is the sense of security and reassurance gained from close, soft physical contact with an attachment figure.
Question 3
Outline the procedure used in Harlow’s animal study of attachment.
[4 marks]
reveal the mark scheme and indicative content
Mark scheme
AO1 = 4
Award 1 mark for each relevant point, up to 4 marks.
Indicative content
Infant rhesus monkeys were reared with two surrogate mothers.
One surrogate was made from bare wire.
The other was covered in soft cloth.
In some conditions the wire mother provided milk, while in others the cloth mother provided milk.
Harlow recorded how much time the monkeys spent with each surrogate.
Behaviour could also be observed when the monkeys were frightened or placed in unfamiliar situations.
AQA describes Harlow's procedure as using wire and cloth surrogate mothers and recording time spent with each, including observations under fear conditions.
Example answer
Harlow reared infant rhesus monkeys with two surrogate mothers, one made of wire and one covered in soft cloth. Milk was provided by one of the surrogates. He recorded how much time the monkeys spent with each mother and also observed their behaviour when they were frightened.
Question 4
Outline two findings from Harlow’s research.
[4 marks]
reveal the mark scheme and indicative content
Mark scheme
AO1 = 4
Award up to 2 marks for each finding.
Indicative content
Finding 1
Monkeys spent much more time with the cloth mother than the wire mother.
This preference occurred regardless of which mother provided milk.
This suggests that contact comfort was more important than feeding.
Finding 2
When frightened, monkeys tended to cling to or seek comfort from the cloth mother.
The cloth surrogate appeared to provide a source of security.
Also credit relevant long-term findings:
Maternally deprived monkeys showed poorer sociability.
They could be more aggressive or less skilled at mating.
Some later showed poor parenting of their own offspring.
Example answer
One finding was that the monkeys spent much more time with the cloth mother, even when the wire mother provided the milk. This suggested that contact comfort was more important than feeding. A second finding was that frightened monkeys tended to cling to the cloth mother for security.
Question 5
An infant monkey receives milk from a wire surrogate. After feeding, it spends most of its time clinging to a cloth surrogate.
Use Harlow’s research to explain the monkey’s behaviour.
[4 marks]
reveal the mark scheme and indicative content
Mark scheme
AO2 = 4
Award 1 mark each for:
The wire mother provides food but little physical comfort.
The cloth mother provides soft physical contact.
The monkey's preference for the cloth mother demonstrates contact comfort.
Harlow's findings suggest attachment is not based simply on the caregiver providing food.
Indicative content
AQA credits Harlow's finding that monkeys spent longer with the cloth mother regardless of which surrogate dispensed milk.
Example answer
Although the wire surrogate provides milk, the monkey spends most of its time with the cloth surrogate because it provides contact comfort. Harlow found that monkeys preferred the soft cloth mother regardless of which surrogate provided food. This suggests that attachment depends strongly on physical comfort and security rather than simply feeding.
Question 6
A monkey is placed in an unfamiliar enclosure containing several new objects. It explores when a cloth surrogate is present but freezes when the surrogate is removed.
Explain this behaviour using the concept of a secure base.
[4 marks]
reveal the mark scheme and indicative content
Mark scheme
AO2 = 4
Award 1 mark each for:
The cloth surrogate provides the monkey with security.
Its presence allows the monkey to feel sufficiently safe to explore the unfamiliar environment.
In this sense, the surrogate acts as a secure base from which exploration can occur.
When it is removed, the source of security disappears, resulting in fear or freezing rather than exploration.
Indicative content
Harlow found that monkeys sought the cloth mother when frightened, supporting the idea that the surrogate provided security rather than merely food.
Example answer
The cloth surrogate provides the monkey with a sense of security. When it is present, it acts as a secure base, allowing the monkey to explore the unfamiliar objects while still having a source of comfort nearby. When the surrogate is removed, this security is lost, so the monkey becomes frightened and freezes instead of exploring.
Question 7
A researcher records the following behaviour:
Surrogate providing milk | Mean time with wire mother | Mean time with cloth mother |
Wire mother | 1.4 hours | 15.8 hours |
Cloth mother | 0.8 hours | 16.5 hours |
Describe the pattern shown in the results. Explain what the results suggest about attachment.
[6 marks]
reveal the mark scheme and indicative content
Mark scheme
AO2 = 6
Award up to 3 marks for describing the pattern and 3 marks for explaining its significance.
Indicative content
Pattern
When the wire mother provides milk, monkeys spend only 1.4 hours with it compared with 15.8 hours with the cloth mother.
When the cloth mother provides milk, monkeys spend 16.5 hours with it and only 0.8 hours with the wire mother.
The cloth mother is therefore strongly preferred regardless of which surrogate supplies food.
Conclusion
Feeding alone does not appear to explain attachment.
Soft physical contact or contact comfort appears to be more important.
The findings challenge the idea that attachment forms simply because the caregiver becomes associated with food.
AQA explicitly states that Harlow's findings suggest contact comfort is more important than food and can be used to challenge learning explanations of attachment.
Example answer
The monkeys spend far more time with the cloth mother in both conditions. Even when the wire mother provides milk, they spend 15.8 hours with the cloth mother compared with only 1.4 hours with the wire mother. When the cloth mother also provides milk, time with it rises slightly to 16.5 hours. This suggests that attachment is influenced more strongly by contact comfort than by food, because the monkeys prefer the soft surrogate even when it does not feed them.
Question 8
Explain one scientific strength and one ethical limitation of Harlow’s animal research.
[6 marks]
reveal the mark scheme and indicative content
Mark scheme
AO3 = 6
Award up to 3 marks for the scientific strength and 3 marks for the ethical limitation.
Indicative content
Scientific strength
Harlow used a relatively controlled environment.
The availability of food and type of surrogate could be systematically varied.
Behaviour such as time spent with each surrogate could be directly recorded.
This allows clearer conclusions about the relative importance of food and contact comfort.
Ethical limitation
Infant monkeys were separated from their biological mothers.
Some procedures were designed to produce fear or psychological distress.
The monkeys could suffer long-term social and behavioural consequences as a result of deprivation.
This raises serious concerns about animal welfare.
AQA's 2025 mark scheme explicitly credits separation from natural mothers and Harlow's procedures causing physical or psychological distress as ethical limitations.
Example answer
One scientific strength is Harlow's use of controlled conditions. He could vary which surrogate provided food and measure how much time the monkeys spent with each mother. This helped isolate contact comfort from feeding and allowed clearer conclusions about their effects on attachment.
One ethical limitation is that infant monkeys were separated from their biological mothers and exposed to procedures that could cause considerable psychological distress. Some monkeys also showed long-term social and parenting difficulties, raising serious concerns about the harm caused by the research.
Question 9
Discuss what Harlow’s animal research may tell psychologists about human attachment.
[8 marks]
reveal the mark scheme and indicative content
Mark scheme
Suggested allocation: AO1 = 3, AO3 = 5
7–8 marks: Knowledge of Harlow's findings is accurate and discussion of what they may tell us about human attachment is thorough and effective. The answer is clear, focused and uses appropriate specialist terminology.
5–6 marks: Relevant knowledge and mostly effective discussion of implications for human attachment, although some points lack development.
3–4 marks: Some relevant knowledge is present, but discussion of human attachment is limited or mainly descriptive.
1–2 marks: Very limited knowledge or discussion.
0 marks: No relevant content.
Indicative content
AO1
Infant rhesus monkeys preferred the cloth surrogate to the wire surrogate regardless of which provided food.
Frightened monkeys sought comfort from the cloth mother.
Early deprivation was associated with later social, mating and parenting difficulties.
AO3
The research suggests that contact comfort and security may be more important than feeding in human attachment.
This challenges simple learning explanations that attachment develops because caregivers provide food.
Human research such as Schaffer and Emerson is consistent with the importance of responsiveness rather than feeding alone.
Harlow's findings suggest that severe disruption or neglect of early attachment could have long-term effects on later relationships and parenting.
The work has practical implications for understanding the importance of responsive care for vulnerable children.
However, rhesus monkeys and humans are different species, and human attachment involves more complex cognitive, emotional and social processes.
Harlow's use of a mammalian species arguably makes the research more relevant to humans than some other animal attachment studies, but generalisation should still be cautious.
These are the kinds of links AQA specifically credits when discussing what Harlow may tell us about humans. The 2022 mark scheme highlights contact comfort rather than food, consequences of early neglect, later relationships, practical implications, and supporting human evidence. The examiner report warns that simply evaluating Harlow's methodology is not enough when the question asks what the research tells us about human attachment.
Example answer
Harlow found that infant rhesus monkeys preferred a soft cloth surrogate to a wire surrogate, even when the wire mother provided food. They also sought the cloth mother when frightened. This suggests that contact comfort and security may be more important in attachment than simply receiving food.
This may apply to humans because human infants also appear to form attachments on the basis of sensitive and responsive interaction rather than feeding alone. Harlow's findings therefore challenge learning theory's emphasis on food as the basis of attachment. His research also showed that early deprivation could lead to later social and parenting difficulties, suggesting that poor early attachment experiences may have long-term consequences for human relationships. However, rhesus monkeys are not humans, and human attachments involve more complex social, emotional and cognitive processes. Therefore, Harlow's findings provide useful insights into human attachment, but they should not be generalised directly.
Question 10
Discuss Harlow’s animal study of attachment. Refer to contact comfort and the scientific and ethical issues raised by the research.
[16 marks]
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