LORENZE AND HARLOW
SPECIFICATION: This section addresses the study of Harlow and Lorenz, which are explicitly mentioned in the AQA Psychology specification for animal attachment studies.
KEY TERMS
ALTRICIAL SPECIES
Animals are born helpless and need a lot of parental care before they can survive on their own. They usually have closed eyes, little fur or feathers, and weak muscles at birth. Examples include humans, puppies, and baby birds like robins.
APOSEMATIC
Bright colours or patterns on an animal warn predators that it is toxic or dangerous. For example, poison dart frogs have bright colours to signal their toxicity.
ASSOCIATIVE LEARNING
A type of learning where an animal links two things, such as a stimulus and a response. For example, Pavlov’s dogs learned to associate a bell with food, making them salivate when they heard the bell.
CRITICAL PERIOD
A short, specific time in development when behaviour must be learned, or it won’t develop properly. For example, baby birds must imprint on a caregiver shortly after hatching.
EUSOCIAL
A high level of social organization where individuals live in groups, divide labour and have cooperative care of the young. Bees, ants, and termites are examples of eusocial species.
ETHOLOGY
The scientific study of animal behaviour focuses on natural environments and instinctive actions. Ethologists study behaviours like imprinting, mating, and survival strategies in different species.
FILIAL ATTACHMENT
The strong bond that young animals form with their parents or caregivers shortly after birth. This helps ensure survival by keeping the young close to their caregivers for protection and learning.
FIXED ACTION PATTERNS (FAPs)
Innate, automatic behaviours triggered by a specific stimulus follow a set sequence. Once started, they continue to completion, even if the trigger is removed. For example, a goose rolling an egg back into its nest will complete the action even if it is taken away.
IMPRINTING
A rapid, irreversible form of learning that happens shortly after birth. Young animals attach to and follow the first moving object they see. Lorenz (1935) showed that geese imprinted on him as if he were the first thing they saw.
INNATE BEHAVIOUR
A behaviour an animal is born with rather than one it learns. Examples include fixed action patterns, imprinting, and social releasers. These behaviours have evolved because they help animals survive and reproduce.
INNATE RELEASING MECHANISMS (IRM)
A built-in system in the brain that detects a specific stimulus and triggers an instinctive response. For example, a baby’s cry (stimulus) triggers a mother’s caregiving response.
INSTINCT
It is an automatic, natural behaviour that happens without thinking or learning. Instincts are hardwired into an animal’s brain and help with survival. For example, newborn babies instinctively suckle for milk.
MONOTROPY
Bowlby’s idea is that babies form one special attachment (usually to their mother), which is more important than all other attachments. This bond shapes future relationships and emotional development.
PHYLOGENY
The evolutionary history of a species shows how it has changed over time and how it is related to other species. Scientists study phylogeny by looking at fossils and DNA.
PRECOCIAL SPECIES
Animals born in a more developed state can move, see, or feed themselves shortly after birth. They usually have open eyes, fur, or feathers and can follow their parents immediately. Examples include ducks, horses, and giraffes.
RELEASER; RELEASING MECHANISM (RM)
A specific stimulus that triggers an automatic response. For example, a mother bird feeding a chick is triggered by the chick’s open beak, which acts as a releaser.
SEXUAL IMPRINTING
When early attachment influences later mate preferences. Lorenz found that birds imprinted on humans sometimes preferred humans as mates, showing how early experiences shape attraction.
SOCIAL RELEASERS
Innate behaviours that encourage caregiving from parents. Human babies cry, smile, and clink to get attention and care. These behaviours help form attachments and ensure survival.
WHAT IS ETHOLOGY AND WHY IS IT IMPORTANT?
Ethology is the scientific study of animal behaviour in natural environments, focusing on evolutionary and biological influences. Ethologists study how behaviours develop, their adaptive value, and their evolution over generations. Unlike behaviourists, who emphasise learned behaviours, ethologists believe many behaviours are innate, genetically programmed, and crucial for survival.
Ethology is essential because it helps explain instinctive behaviours such as mating, parenting, communication, and social bonding. Many of these behaviours appear universally across species and emerge even without prior learning, suggesting they are biologically hardwired. The work of ethologists like Konrad Lorenz and Nikolaas Tinbergen has provided valuable insights into how animals, including humans, develop attachment, aggression, and social behaviours.
ETHOLOGY APPLIED TO ATTACHMENT
Ethology has been crucial in shaping our understanding of human attachment, mainly through the work of John Bowlby.
Imprinting (Lorenz, 1935) – Lorenz’s research on geese demonstrated that some species form instant and irreversible attachments to a caregiver during a critical period. This concept influenced Bowlby’s belief that human infants have a biologically determined window for forming strong attachments.
Innate Attachment Behaviours – Ethologists argue that attachment is an evolved survival mechanism. Human infants are born with social releasers (e.g., crying, smiling) that trigger adult caregiving responses, ensuring protection and care.
Monotropy and the Secure Base (Bowlby, 1969) – Bowlby applied ethological principles to human attachment, proposing that infants develop a primary attachment (monotropy) to a key caregiver who provides a secure base for exploration.
The Sensitive Period – Similar to imprinting, Bowlby suggested a sensitive period in which attachment must form. While not as rigid as Lorenz’s critical period, failure to form a secure attachment during early childhood can lead to social and emotional difficulties later in life.
Ethological research has shaped modern attachment theory by showing that attachment is biologically programmed rather than purely learned. It emphasises the adaptive function of early bonds, highlighting their role in emotional security, social development, and survival.
KONRAD LORENZ (1935) AND IMPRINTING
Konrad Lorenz's research in 1935 focused on attachment, specifically imprinting in goslings, shedding light on how attachment functions in animals.
Lorenz was a key figure in ethology, the scientific study of animal behaviour, particularly in natural environments. His work focused on how behaviour develops and the role of innate biological processes in shaping social bonds. One of his most influential contributions was his research on imprinting, a process where certain animals form strong, irreversible attachments to the first moving object they see after birth.
LORENZ'S STUDY
AIMS:
Lorenz's aim was to investigate how attachment behaviours in goslings develop and to understand the biological mechanisms behind imprinting.
The hypothesis was that goslings would form attachments to the first moving object they encountered after hatching
DESIGN:
EXPERIMENTAL DESIGN: Independent groups design.
SETTING: Field experiment (naturalistic setting with controlled conditions).
VARIABLES:
(IV): Whether the goslings were hatched artificially (by Lorenz) or naturally (by their mother).
(DV): Who the goslings followed after hatching (Lorenz, their mother, or nobody).
DATA COLLECTION METHODS:
Observation – Lorenz visually recorded which figure the goslings followed.
Longitudinal Tracking – Followed goslings over time to check if imprinting remained.
Possible Film Recording – Cine cameras were available in 1935, though primary records were field notes from observations.
METHOD
Lorenz conducted his imprinting experiments using a clutch of greylag goose eggs. These eggs were laid by a greylag goose, indicating they came from a single mother. He divided the eggs into two conditions:
One batch was left with the biological mother and incubated by her and left to hatch naturally.
The other batch was incubated artificially, ensuring that Lorenz was the first moving object they saw upon hatching.
OBSERVATION OF FOLLOWING BEHAVIOUR – After hatching, both groups were observed to determine which figure they followed.
LATER TESTS – When the groups were mixed, Lorenz checked whether the goslings switched following behaviour or stayed with their imprinted figure.
CRITICAL PERIOD STUDY
Lorenz further examined whether imprinting could occur outside a specific timeframe by varying the time he appeared after the goslings hatched.
Lorenz deliberately varied the time between birth and when the goslings first saw a moving object.
This allowed him to systematically measure the critical period by determining the latest point at which imprinting could still occur
FINDINGS:
After hatching, Lorenz's goslings imprinted on him, treating him as their mother and following him everywhere. Meanwhile, the goslings raised by the biological mother were imprinted on her instead.
When Lorenz marked and mixed both groups to test whether imprinting was reversible, the goslings who imprinted on him continued to follow him. In contrast, the others remained with their biological mother. This demonstrated that imprinting was a fixed and irreversible process once established.
Lorenz also found that imprinting had long-term effects. Birds that imprinted on humans showed sexual imprinting, meaning that when they matured, they exhibited courtship behaviours towards humans rather than their species.
Critical Period: Imprinting had to occur within a short window after birth, or it would not happen at all.
Lorenz found that imprinting only occurred within a critical period of 0-24– hours after hatching.
Imprinting begins almost immediately after hatching (0 hours).
The strongest imprinting occurs within the first few hours (likely 0–5 hours).
It remained possible up until around 16 hours.
After 16 hours, the likelihood of imprinting drops.
By 24 hours, most goslings struggle to imprint, and by 48 hours, it is nearly impossible.
CONCLUSIONS
Lorenz believed imprinting was an adaptive behaviour that increased survival, as it ensured that young birds remained close to a caregiver who could provide protection and food.
OTHER RESEARCH ON IMPRINTING
SPALDING (1873)
Douglas Spalding conducted early experiments on imprinting, observing that young birds would follow the first moving object they encountered. His work laid the foundation for later studies on imprinting and instinctive behaviour. Spalding (1873) is often overlooked in discussions of imprinting because his work was published long before the formal development of ethology as a field, and he did not use the term "imprinting" himself. His studies were largely forgotten until later researchers, such as Lorenz, revisited similar ideas.
LORENZ'S PEACOCK STUDY
In 1952, Konrad Lorenz documented a case of sexual imprinting involving a peacock raised in a zoo's reptile house. The peacock, upon hatching, first encountered giant tortoises. As an adult, it exclusively directed courtship behaviors toward these tortoises, indicating it had imprinted on them during its early development.
LÖHRL (1959)
Hans Löhrl studied habitat imprinting in collared flycatchers. He found that young birds needed to fly and explore their environment in order to imprint on their home grounds, suggesting that imprinting is not limited to parental attachment but can extend to habitat selection.
KLOPFER & GOTTLIEB (1962)
Peter Klopfer and Gilbert Gottlieb investigated auditory and visual imprinting in domestic ducks. Their research highlighted the importance of different sensory modalities in imprinting, showing that visual exposure was not the only factor influencing the process.
BATESON (1966)
Patrick Bateson explored the flexibility of imprinting, arguing that it is not entirely fixed and can be influenced by later experiences. His work challenged the notion that imprinting is an all-or-nothing process and suggested that some level of modification is possible over time.
GUITON (1966)
Guiton exposed newly hatched leghorn chicks to yellow rubber gloves during their critical period. The chicks imprinted on the gloves, demonstrating that imprinting could occur on inappropriate objects and was not limited to living creatures. However, he later found that these chicks attempted to mate with gloves in adulthood, reinforcing the idea that early imprinting has long-term consequences.
These studies collectively contribute to our understanding of imprinting, showing its significance across different species and how factors such as sensory input, environment, and flexibility influence the process.
EVALUATION OF LORENZ’S ANIMAL STUDY
EVALUATION OF RESEARCH
Lorenz’s research on imprinting has been highly influential and has been replicated across many species of birds, both in natural settings and laboratory experiments. His findings provided strong evidence that imprinting is an innate process, occurring within a critical period soon after birth. This has been observed not only in geese but also in ducks, chickens, and other precocial birds, confirming that young animals instinctively form an attachment to a caregiver figure without the need for reinforcement.
However, later research has challenged the rigidity of Lorenz’s imprinting theory. Bateson (1966) argued that imprinting is not an instant, irreversible process but rather a gradual one that can be influenced by later experiences. He found that while animals typically imprint on the first moving object they see, this attachment can sometimes be modified if they are later exposed to a different stimulus. His findings led to a re-evaluation of critical periods, suggesting that these developmental windows are more flexible than Lorenz initially proposed.
Similarly, Guiton (1966) demonstrated that imprinting could occur on inappropriate objects and that its effects were not always permanent. He found that chicks who imprinted on yellow rubber gloves could later learn to prefer more appropriate social partners, further supporting the idea that imprinting is not entirely fixed and can be modified over time.
Together, Bateson and Guiton challenged the traditional view that imprinting is rigid and irreversible, instead highlighting the plasticity of behaviour and the interaction between early and later experiences in shaping attachment and social development. While Lorenz’s work remains foundational in ethology, these later studies have refined our understanding of how flexible and adaptable imprinting may be in certain circumstances.
However, despite the evidence from Bateson (1966) and Guiton (1966) suggesting that imprinting is more flexible than Lorenz originally claimed, it remains largely instinctive. The process is still biologically driven, occurring without conscious effort or reinforcement, and plays a key role in early survival and later social behaviours. However, certain confounding factors—such as pheromonal cues, seasonal changes, and environmental influences—suggest that imprinting does not act in isolation but interacts with other instinctive mechanisms that regulate behaviour.
One major factor is pheromonal communication, particularly in sexual imprinting. Many bird species release pheromones during mating seasons, which influence mate selection alongside early attachment experiences. This means that while birds often prefer mates resembling their initial attachment figure, this preference may be further shaped by chemical cues that signal reproductive fitness. This suggests that imprinting may be instinctive but not entirely deterministic, as birds rely on multiple biological and environmental signals to guide mate choice.
Additionally, seasonal breeding cycles regulate when birds are receptive to mating and social bonding. If imprinting were the sole determinant of mate choice, birds would theoretically seek out mates at any time. However, species-specific hormonal changes and environmental triggers (such as day length and food availability) activate mating behaviours only during particular seasons. This indicates that imprinting sets an initial preference, but other instinctive mechanisms—such as hormonal fluctuations and external cues—further shape social and reproductive behaviours.
Therefore, while imprinting is an innate and instinctive process, its effects can be modulated by later biological and environmental influences. However, this flexibility is not necessarily the result of learning, as some researchers have suggested. Instead, imprinting remains fundamentally a biologically driven process, with modifications occurring within the constraints of instinctive mechanisms such as pheromonal cues, hormonal cycles, and species-specific environmental adaptations. This reinforces Lorenz’s original idea that imprinting is an evolutionarily programmed behaviour, even if it is not as rigid as he initially proposed.
EVOLUTIONARY SURVIVAL ADVANTAGES
ENSURES SPECIES RECOGNITION
In natural conditions, imprinting on the mother ensures that the young bird later recognises and socialises with its own species.
PROTECTION FROM PREDATORS
Survival Advantage – Imprinting ensures that newborn animals remain near a caregiver, reducing their risk of predation and increasing their chances of receiving food and protection.A newly hatched bird is vulnerable. By imprinting on and following a parent, it stays within the safety of the group, reducing the risk of predation.
HAPPENS INSTINCTIVELY
Unlike learning through reinforcement, imprinting happens quickly and permanently, meaning the animal doesn’t waste time figuring out who to follow.
WHY IT IS IRREVERSIBLE
Once the imprinting process is complete, the attachment is fixed for life. This prevents confusion and ensures that the animal doesn’t mistakenly imprint on a predator or an inanimate object after the critical period has passed. Critical Period – Imprinting must occur within a specific time window (the critical period, typically within the first 16 hours for birds), after which attachment does not form. This concept influenced later attachment theories in humans, particularly Bowlby’s critical period for human attachment.
WHY IT HAPPENS IN A CRITICAL PERIOD
Filial imprinting is only possible within a specific time frame (e.g. 0–16 hours in geese).
This ensures that imprinting happens before the young animal is exposed to potential dangers.
If imprinting were flexible throughout life, it could create confusion and lead to survival disadvantages.
Sexual Imprinting – Lorenz's research suggested that early attachment experiences influence mate selection later in life, with animals preferring mates that resemble their first attachment figure.
IMPRINTING AND ETHOLOGY
Lorenz’s work was foundational in ethology, demonstrating that attachment behaviours in animals are innate and biologically programmed, rather than learned through experience, as behaviourists claimed. Behaviourism, which dominated psychology at the time, proposed that all behaviours, including attachment, were learned either through classical conditioning (association) or operant conditioning (reinforcement). Lorenz challenged this view by showing that imprinting occurs naturally within a critical period, without the need for reinforcement or repeated exposure. His research provided strong evidence that certain behaviours are species-specific and develop through evolution, rather than being shaped purely by learning. Ethologists study these instinctive behaviours, which appear universally in a species and are triggered by environmental stimuli. By establishing imprinting as an evolutionary adaptation, Lorenz demonstrated that attachment is genetically pre-programmed rather than acquired through conditioning.
LORENZ’S IMPRINTING THEORY APPLIED TO HUMAN ATTACHMENT
Although Lorenz conducted his study on geese, he did not claim that human attachment was identical to imprinting in birds. He knew that geese are a precocial species, meaning they are born in a relatively developed state and can move independently shortly after hatching. In contrast, humans are an altricial species, born highly dependent and requiring prolonged parental care. However, Lorenz believed imprinting provided evidence for a biological basis of attachment in species that rely on parental care for survival.
Because all species share a common ancestor, he argued that attachment, like imprinting, is an evolutionary adaptation. Bowlby later extrapolated this idea to humans and hypothesised that just as goslings imprint on a caregiver to ensure survival, human infants instinctively seek proximity to a caregiver to maximise their chances of protection, nourishment, and survival. This was the basis of Bowlby’s attachment theory, which proposed that human attachment is innate and biologically programmed, rather than learned through reinforcement, as behaviourists suggested.
DIFFERENCES
However, while imprinting and human attachment share biological underpinnings, they differ in several ways:
Human attachment is more flexible than imprinting – Lorenz described imprinting as occurring within a rigid critical period (the first few hours or days after hatching). Bowlby initially proposed a crucial period in human attachment (up to 2.5 years), but later research by Rutter et al. (1981) suggested that this period is more sensitive than absolute, extending up to six months.
Human infants form multiple attachments – Imprinting typically occurs with a single attachment figure, usually the first moving object seen. In contrast, Schaffer and Emerson (1964) found that human infants form multiple attachments to different caregivers, although there is often a primary attachment figure.
Human attachment is not necessarily irreversible – Lorenz found that once imprinting occurred, it was permanent and influenced future mate preferences (sexual imprinting). Attachment disruption can lead to severe developmental issues in humans, but attachment can sometimes be repaired or transferred to new caregivers, particularly if intervention occurs during a sensitive period (Rutter et al., 1998 – Romanian Orphan Study).
Humans do not rely on fixed action patterns (FAPs) or filial attachment – In birds, imprinting is controlled by fixed action patterns, which are innate, automatic behaviours triggered by a specific stimulus (e.g. the first moving object seen after birth). Birds form filial attachments, meaning they instinctively bond with and follow their caregiver for survival. Humans, however, do not have a simple following response and instead develop attachments through interaction, emotional bonding, and learned experiences.
Cognitive differences shape human attachment – Human attachment is far more complex than imprinting in birds due to differences in brain development, consciousness, and language. The human brain is larger and more advanced, allowing for deep emotional bonding, communication, and long-term relationship-building. Unlike birds, which imprint based on immediate survival needs, human attachment is social and reciprocal, shaped by shared experiences and emotional understanding rather than instinct alone.
Birds often reject their young once independent, while humans form lifelong attachments – In many bird species, parents reject or fail to recognise their offspring once they become independent, showing no emotional connection beyond the early developmental stage. In contrast, human attachments last a lifetime, and parental bonds often strengthen over time rather than disappear.
SIMILARITIES
Despite these differences, imprinting and human attachment demonstrate the evolutionary necessity of forming bonds for survival. In both cases, young animals or infants who fail to attach to a caregiver face severe consequences, including an increased risk of death or developmental issues. This aligns with the broader ethological perspective, which sees attachment as an adaptive behaviour that has evolved to increase survival chances across species.Despite these differences, imprinting and human attachment demonstrate the evolutionary necessity of forming bonds for survival. In both cases, young animals or infants who fail to attach to a caregiver face severe consequences, including an increased risk of death or developmental issues.
Furthermore, imprinting and human attachment share key similarities that support Bowlby’s attachment theory:
THE CONTINUITY HYPOTHESIS– Just as geese who fail to imprint struggle with later social behaviours, human children deprived of early attachment show long-term developmental issues. Rutter et al. (1998) found that Romanian orphans who lacked early attachments displayed disinhibited attachment (indiscriminate friendliness, difficulty forming close bonds). However, Robertson and Robertson (1971) showed that the effects of temporary deprivation could be reversed with emotional support, further highlighting differences between imprinting and human attachment. early attachments influence later relationships – Lorenz found that imprinting affects later mate choice, a phenomenon known as sexual imprinting. Birds often prefer mates that resemble their first attachment figure. This parallels Bowlby’s continuity hypothesis, which suggests that early attachment experiences shape later relationships. Hazan and Shaver (1987) extended this idea in their "love quiz" study, showing that securely attached infants were more likely to have stable adult relationships, while insecurely attached children experienced difficulties in later romantic bonds.
CRITICAL PERIODS – Both imprinting and human attachment occur within a specific developmental window. Lorenz demonstrated that geese must imprint within a critical period (first 16 hours), after which imprinting does not occur. Similarly, Bowlby initially proposed that human attachment must form within a crucial period (up to 2.5 years) to avoid long-term emotional and social consequences. While Rutter et al. (1998) later suggested this is a sensitive period rather than absolute, children who lacked early attachments—such as those in Romanian orphanages—struggled with later bonding, mirroring the irreversible effects of failed imprinting in birds.
ATTACHMENT IS INNATE – Imprinting ensures that young birds stay close to their caregiver for protection, food, and survival. Similarly, human attachment is an adaptive behaviour that increases an infant’s chances of survival by keeping them near a caregiver who provides nourishment and protection from predators.
ROLE OF SOCIAL RELEASERS – Lorenz found that imprinting in birds is triggered by movement, meaning hatchlings instinctively follow the first moving object they see. This resembles Bowlby’s concept of social releasers, where human infants are born with innate behaviours such as crying, smiling, and clinging that elicit caregiving responses and encourage bonding with an attachment figure.
While imprinting in birds is a simpler, instinctive process, and human attachment involves emotion, cognition, and flexibility, both share biological foundations that support Bowlby’s evolutionary theory of attachment. The continuity hypothesis, critical period, role of social releasers, and long-term effects of early bonding experiences all suggest that early attachment plays a crucial role in shaping future social and emotional development across both humans and other species
SIMILARITIES BETWEEN IMPRINTING AND HUMAN ATTACHMENT
Despite the differences between imprinting and human attachment, both demonstrate the evolutionary necessity of forming bonds for survival. In both cases, failure to establish an early bond can lead to severe consequences, including increased vulnerability, social difficulties, and developmental issues. Ethologists argue that attachment, like imprinting, is an adaptive behaviour that has evolved to increase the chances of survival across species.
THE CONTINUITY HYPOTHESIS
Early attachments influence later relationships in both birds and humans. Lorenz found that imprinting affects later mate choice, a phenomenon known as sexual imprinting, where birds often prefer mates resembling their first attachment figure. This supports Bowlby’s continuity hypothesis, which suggests that early attachment experiences shape later social and romantic relationships. Hazan and Shaver (1987) extended this idea in their "love quiz" study, showing that securely attached infants were more likely to develop stable adult relationships, while insecurely attached children were more likely to struggle with intimacy. Similarly, Rutter et al. (1998) found that Romanian orphans who lacked early attachments displayed disinhibited attachment, characterised by indiscriminate friendliness and difficulty forming close bonds. However, privation (absence of attachment as demonstrated with feral children and the Romanian orphans) is extremely rare. Robertson and Robertson (1971) demonstrated that the effects of maternal deprivation (disrupted attachment) could be reversed with emotional support, further highlighting the differences between imprinting and human attachment.
CRITICAL PERIODS
Both imprinting and human attachment occur within a specific developmental window. Lorenz demonstrated that geese must imprint within a critical period (first 16 hours), after which imprinting does not occur. Similarly, Bowlby initially proposed that human attachment must form within a crucial period (up to 2.5 years) to avoid long-term emotional and social consequences. Rutter et al. (1998) later argued that this period is sensitive rather than absolute, showing that children adopted after six months had greater difficulties bonding, but that attachment formation was still possible. This mirrors the irreversible effects of failed imprinting in birds, where failure to imprint within the critical window results in long-term social deficits.
ATTACHMENT IS INNATE
Both imprinting and human attachment are biologically programmed to ensure survival. Imprinting in birds keeps hatchlings close to their caregiver for protection, food, and learning essential survival behaviours. Similarly, Bowlby proposed that human attachment is an adaptive behaviour, ensuring that infants stay near a caregiver who provides nourishment and protection from danger.
ROLE OF SOCIAL RELEASERS
Lorenz found that movement triggers imprinting in birds, meaning hatchlings instinctively follow the first moving object they see. This resembles Bowlby’s concept of social releasers, where human infants use innate behaviours such as crying, smiling, and clinging to elicit caregiving responses and maintain close proximity to an attachment figure.
CONCLUSION
While imprinting in birds is an instinctive and rigid process, and human attachment involves emotion, cognition, and flexibility, both share biological foundations that support Bowlby’s evolutionary theory of attachment. The continuity hypothesis, critical period, role of social releasers, and long-term effects of early bonding experiences all suggest that early attachment plays a crucial role in shaping future social and emotional development across species.
MARK SCHEMES
problems of extrapolation to attachment in human infants – what applies to non-human species may not also apply to human infants• difference in nature and complexity of the bond• human mothers show more emotional attachment to the young than birds• humans may be able to form attachments at any time• DNA differences/human brain size differences may reduce generalisability
Possible discussion points:• problems of generalising findings from animal studies to humans – argument that, of the two, Harlow’s study (mammalian species) may be more relevant to human experience• implications of imprinting/critical period for human attachment (Lorenz) – ‘window of opportunity’ in which attachments must be formed otherwise this may lead to negative long-term consequences (credit reference to Bowlby’s work in this context, eg maternal deprivation)• implications of early neglect (Harlow) – long-term consequences of poor attachment in childhood for future relationships, eg with own children (again, credit reference to Bowlby in this context – internal working model)• argument that the critical period may be more of a ‘sensitive period’ in humans as studies have demonstrated how children have been able to recover from early deprivation, eg Romanian orphan studies• practical value of research, eg for social work, identifying risk factors in vulnerable children• implications for theories of attachment, eg Harlow’s suggestion that contact comfort/sensitive responsiveness is more important than food contradicts learning theory• support from human studies, eg Schaffer and Emerson Glasgow study supports the idea that responsiveness may be more important than food.
also credit reference to the case study of sexual imprinting in a peacock
HARRY HARLOW MONKEYS
HARLOW’S RESEARCH ON ATTACHMENT
Harry Harlow, an American psychologist, conducted a series of controversial but groundbreaking studies on rhesus monkeys to investigate the nature of attachment and maternal bonding. His research challenged the behaviourist "cupboard love" theory, which suggested that infants become attached to their caregivers simply because they provide food. Instead, Harlow argued that attachment is biologically driven and primarily based on contact comfort rather than nourishment.
His studies provided strong empirical evidence that comfort and security are fundamental biological needs, shaping modern attachment theory and supporting Bowlby’s evolutionary perspective.
HARLOW’S EARLY RESEARCH AND WHY HE USED RHESUS MONKEYS
Harlow began his career at the University of Wisconsin–Madison in the 1930s, initially focusing on learning, cognition, and problem-solving in primates. To study how primates develop problem-solving abilities, he established a breeding colony of rhesus macaques in 1932, allowing him regular access to infant primates for controlled studies.
He chose rhesus monkeys because:
They are primates with complex social behaviours, making them more comparable to humans than other animal models.
They are altricial species, meaning they are born helpless and require prolonged parental care, unlike precocial species such as geese.
They develop strong emotional bonds with their mothers, similar to human infants.
Harlow’s early observations contradicted behaviourist views—even when raised with food and physical care, nursery-reared monkeys displayed emotional distress and social impairments compared to mother-reared monkeys. This inspired him to investigate the role of maternal attachment further.
HARLOW’S STUDY 1959 – ‘THE ORIGINS OF LOVE’
Harry Harlow researched to show that attachment is not necessarily a learned process due to feeding bonds. His study challenged the behaviourist claim that infants form attachments solely because caregivers provide food. Harlow was led to this experiment after noticing that infant rhesus monkeys in his lab cling to soft cloth nappies (diapers) placed in their cages, showing attachment-like behaviours despite the nappies not providing food.
To investigate this further, Harlow separated infant rhesus monkeys from their biological mothers shortly after birth and placed them in isolation cages with two surrogate mother figures—one made of wire and another covered in soft cloth. Both surrogate mothers were in the cage simultaneously, allowing the monkeys to choose which one to seek comfort from. In one condition, the wire mother had a milk bottle attached to provide food, while the cloth mother had no milk. In another variation, the cloth mother provided milk while the wire mother did not.
Harlow observed that regardless of which mother provided food, the infant monkeys spent significantly more time clinging to the cloth mother, only visiting the wire mother briefly when hungry. When frightened, they ran to the cloth mother for reassurance rather than the wire mother, demonstrating the importance of contact comfort—the feeling of security and safety derived from physical closeness.
Further variations of the study reinforced these findings. When placed in an unfamiliar room filled with toys, monkeys with access to the cloth mother used her as a secure base for exploration, similar to human infants in Bowlby’s attachment theory. In contrast, monkeys in the presence of only the wire mother displayed fear, huddling in a corner and avoiding interaction with their surroundings.
Harlow also investigated the long-term effects of maternal deprivation. Monkeys raised without real mothers developed abnormal social behaviours, including difficulty interacting with other monkeys, heightened aggression, and severe difficulties in mating. When female monkeys raised in isolation had offspring of their own, many neglected or even physically harmed their babies. Harlow concluded that early experiences of attachment and comfort were crucial for healthy social and emotional development.
Additionally, he identified a critical period for social development. If the monkeys were exposed to peers before three months of age, they could recover socially. However, those deprived of maternal and peer interactions for six months or more exhibited irreversible damage.
Harlow’s findings supported Bowlby’s claims that attachment is biological and essential for emotional development. His research demonstrated that attachment is not purely based on feeding but on comfort and security. However, his work remains one of the most ethically controversial studies in psychology due to the distress inflicted on the infant monkeys.
THE WIRE AND CLOTH MOTHERS EXPERIMENT (1959)
AIM
Harlow aimed to determine whether attachment is based on feeding (as behaviourists claimed) or physical comfort and security.
PROCEDURE
Infant rhesus monkeys were separated from their biological mothers at birth and raised in isolation.
They were placed in cages with two artificial surrogate mothers:
The wire mother is made of bare wire mesh and is equipped with a feeding bottle.
The cloth mother was covered in soft terry cloth but provided no food.
The monkeys were divided into two conditions:
The wire mother fed one group.
The cloth mother fed one group.
Harlow observed how much time the infants spent with each surrogate and how they reacted when frightened.
FINDINGS
Regardless of which mother provided food, all monkeys spent significantly more time with the cloth mother.
When frightened, the monkeys ran to the cloth mother for comfort, even if the wire mother had fed them.
When placed in an unfamiliar room, monkeys with the cloth mother used her as a secure base to explore, while those with only the wire mother showed fear and withdrawal.
Monkeys raised only by the wire mother suffered severe emotional distress, including diarrhoea and signs of anxiety.
CONCLUSIONS
Harlow’s findings directly contradicted behaviourist theories, showing that attachment is not formed through feeding alone. Instead, he introduced the concept of contact comfort, arguing that:
Attachment is biologically driven and is not merely learned through reinforcement.
Comfort and security are primary needs, as crucial as food.
The bond between an infant and its caregiver is based on emotional security, not just nourishment.
These findings supported Bowlby’s attachment theory, reinforcing that attachment has an evolutionary basis and is crucial for survival.
VARIATIONS AND FURTHER EXPERIMENTS
THE OPEN-FIELD TEST
Infant monkeys were placed in a new environment with unfamiliar objects.
When the cloth mother was present, they explored confidently but returned to her when anxious.
When only the wire mother was present, they froze in fear and showed no exploratory behaviour.
This supported Bowlby’s "secure base" concept, where infants use their caregiver as a foundation for exploration.
THE FEAR TEST
A mechanical teddy bear was introduced to frighten the monkeys.
With the cloth mother present, monkeys clung to her for comfort before approaching the object.
With only the wire mother (or no mother), the monkeys cowered in fear and refused to engage with the object.
This experiment reinforced the idea that attachment provides emotional security beyond physical survival.
TOTAL ISOLATION EXPERIMENTS
Some monkeys were raised in total isolation with no surrogate mother for different durations (3 months, 6 months, 12 months).
Monkeys isolated for less than 3 months could recover when reintroduced to peers.
Monkeys isolated for over 6 months developed severe emotional and social disorders, including:
Rocking, self-mutilation, and extreme withdrawal.
Inability to interact socially when later introduced to other monkeys.
Abnormal sexual behaviour as adults.
Neglect or abuse of their offspring when they became parents.
These findings strengthened Bowlby’s concept of a "critical period", showing that early attachment experiences are crucial for normal development and that long-term deprivation can have irreversible effects.
"MONSTER MOTHERS" EXPERIMENT
Harlow created surrogate mothers who rejected, attacked, or blasted air at their infants.
Some monkeys clung to their abusive surrogate despite the mistreatment, showing how deeply ingrained attachment behaviours are.
This suggested that infants can become attached even to unresponsive or harmful caregivers, which has implications for understanding abusive human relationships.
EVALUATION
HOW HARLOW CONTRADICTED BEHAVIOURISM
Harlow’s research directly challenged behaviourist theories that claimed attachment was learned through classical or operant conditioning.
If the attachment was solely based on food provision (classical conditioning), the monkeys should have preferred the wire mother that fed them—but they did not.
Both mothers should have been equally effective if the attachment was formed through reinforcement (operant conditioning). However, only contact comfort provided emotional security.
Instead, Harlow supported a biological explanation, showing that:
Attachment is an innate process, not a learned behaviour.
Emotional security is as vital as nourishment for infant survival.
IMPACT OF HARLOW'S RESEARCH
SUPPORTING BOWLBY’S THEORY
Harlow provided strong empirical support for Bowlby’s evolutionary theory of attachment, reinforcing the idea that attachment is biologically programmed and essential for survival.
His work validated the idea of a critical period for forming attachments.
CHANGING CHILDCARE PRACTICES
At the time, hospitals discouraged physical contact between mothers and infants to avoid "spoiling" them.
Harlow’s research helped shift attitudes toward the importance of touch, comfort, and caregiver bonding.
UNDERSTANDING SOCIAL DEPRIVATION
His studies contributed to research on orphaned children, foster care, and the effects of maternal deprivation.
His findings influenced changes in adoption and childcare policies, emphasising the importance of early bonding and emotional care.
ETHICAL REFORMS IN ANIMAL RESEARCH
Harlow’s experiments were highly controversial due to the severe distress inflicted on the monkeys.
His work led to stricter ethical regulations in animal research, ensuring more significant consideration for animal welfare.
Ethical concerns remain a significant issue in Harlow’s research. The rhesus monkeys were subjected to extreme distress, experiencing prolonged separation and emotional harm. Many suffered from severe social dysfunction and an inability to form relationships later in life, raising questions about the ethical costs of such experimentation. The long-term consequences of maternal deprivation in these monkeys were severe, with many struggling to integrate into regular social groups or care for their offspring.
However, despite these ethical issues, Harlow’s study provided groundbreaking insights into the importance of early attachment and emotional security, influencing childcare practices and policies on institutional care. Many argue that while the ethical cost was high, the study's real-world applications in improving human and animal welfare justify its significance. His findings challenged the behaviourist view that attachment is solely based on feeding and provided empirical support for Bowlby’s attachment theory, reinforcing that comfort and security are fundamental to emotional development.
One major criticism of Harlow's study is that it focused on monkeys and their attachment behaviour, which may not directly represent human behaviour due to species differences and A significant criticism of Harlow’s study is that it focused on monkeys, which may not directly represent human attachment behaviour due to species differences. Unlike rhesus monkeys, humans have a more complex cognitive capacity, allowing them to reflect on their relationships, form abstract concepts of love and security, and adapt their attachment behaviours based on social and cultural influences. Human infants are also raised within structured social environments, where multiple caregivers may contribute to attachment, whereas monkeys rely more on instinctual bonding.
This raises concerns about external validity, as findings from rhesus monkeys may not fully generalise to human infants. Additionally, there are internal validity concerns, as some argue that the study primarily demonstrates attachment behaviour in monkeys rather than providing definitive conclusions about human attachment. However, given that rhesus monkeys share approximately 94% of their DNA with humans, their social and emotional behaviours bear significant similarities, such as seeking comfort, forming bonds, and displaying distress when separated. This suggests that while caution is necessary when applying Harlow’s findings to human attachment, they may still offer valuable insights into the fundamental need for emotional security in early development.
Further support for Harlow’s conclusions comes from Schaffer and Emerson’s research on human infants, which found that babies did not necessarily form attachments with those who fed them but rather with individuals more sensitive to their needs. This aligns with Harlow’s findings, where the infant monkeys preferred the cloth mother, seeking comfort and security rather than simply associating attachment with food.
ASSESSMENT
Describe Lorenz's research into attachment (4 marks).
Describe Harlow’'s research into attachment (4 marks).
Outline Lorenz’s and Harlow’s animal studies of attachment. Discuss what these studies might tell us about human attachment. (5 marks)
Other than ethical issues, explain one limitation of using animals to study attachment in humans (4 marks)
Describe what animal studies into attachment have revealed (4 marks).
Outline one animal study into attachment, including the researchers' methods and findings (6 marks).
Outline and evaluate animal studies of attachment (12 marks for AS, 16 marks for A-level).
Outline Lorenz’s and Harlow’s animal studies of attachment. Discuss what these studies might tell us about human attachment (16 marks)
Animal Studies
Lesson 4: Animal Studies
• To be able to outline two animal studies into attachment
• To be able to evaluate these studies in terms of ethics and applicability
Video Questions
Watch the following video and answer the questions: Video Link
1. What is imprinting? (2 marks)
2. Why did the duckling imprint onto the Wild Robot? (2 marks)
3. Suggest two social releasers that made the Robot want to take care of the duck. (2 marks)
Psychologists use animal studies when studying attachment behaviour
a. Outline one practical reason for using animals rather than humans when studying attachment behaviour. (2 marks)
b. Suggest one ethical reason for using animals rather than humans when studying attachment behaviour. (2 marks)
Total Marks:
Bowlby’s Theory of Attachment
Bowlby (evolutionary psychologist) suggested that humans and animals are born with an innate tendency to form attachments as they have an evolutionary advantage. Bowlby suggests that, if a human/animal does not form an attachment (privation) or their attachment is damaged (maternal deprivation), this can have a negative impact, including poor peer relationships during childhood and adulthood, difficulty forming romantic relationships, struggles with parenting their own children, cognitive and mental development issues, delayed physical growth, and emotional struggles, potentially leading to “affectionless psychopathy.
Lorenz Study (Konrad Lorenz, 1975)
Reference: Page 78-79
YouTube: Konrad Lorenz - Science of Animal Behavior (1975)
1. What was the aim of the study?
2. What did they do?
3. What did they find out?
4. What is meant by sexual imprinting?
5. How does this support/go against Bowlby’s theory?
Harlow’s Study on Dependency in Monkeys
Reference: Page 78-79
YouTube: Harlow’s Studies on Dependency in Monkeys
1. What was the aim of the study?
2. What did they do?
3. What did they find out?
4. What is meant by maternal deprivation?
5. How does this relate to adult monkeys?
6. Explain the critical period for normal development.
7. How does this support/go against Bowlby’s theory?
Evaluation of Animal Studies
What is good about using animals for psychological research? What is bad about it?
Additional AO3 Questions
1. What did Regolin and Vallortigara (1995) discover about imprinting?
2. How can research be used in the real world?
3. Can we generalise gosling behaviour to humans?
4. Can we generalise primate behaviour to humans?
Apply It Question: Answer the Apply question on page 80.
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Crossword Activity: Attachment Terms
(AQA Psychology Year 1 & AS Activity)
Across
1. The second stage of attachment around 2-7 months.
2. Attachments formed in addition to the first specific one.
3. An observation where participants are unaware that they are being watched.
4. Term used to describe bird behaviour where they follow the first moving object they see after birth.
5. Where Schaffer and Emerson’s babies came from.
6. Synchrony is the coordinated way in which mother and baby reflect each other’s emotions and actions.
Down
2. The way in which a parent and child respond to each other’s signals.
3. Behaviour characterised by the regular return of a baby to the caregiver is called ______ base behaviour.
4. The time period during which the development of a behaviour must occur, or it never will.
5. An observation in which a behaviour is watched in the setting in which it usually occurs.
