Initially, it was considered that if research was too controversial or unethical for humans, it was conducted on animals instead. From the 1930s to much later, animal studies of attachment were widely conducted. Although they are still used today, it is much less common because of the controversy and ethical issues that come with them.
- We will start by outlining animal studies of attachment: Lorenz and Harlow conducted.
- Then we will outline the procedure used in one study of animal research, i.e. the research of Lorenz.
- After, we will describe and evaluate animal studies of attachment conducted by Harlow.
- Finally, we will evaluate and learn the implications of animal studies of attachment and understand the limitations of using animals to study attachments in humans.
Animal Studies of Attachment Lorenz & Harlow
What and why are animal studies used in psychology?
Animal studies in psychology are conducted on non-human species to learn more about how humans function.
Some animals are used frequently because of the similarity of their brain makeup to humans.
For example, common animal subjects include monkeys, mice, and rats.
Animal studies aim to generalise the findings and knowledge to humans. Some animals have a short gestation period, and because they reproduce more quickly, researchers can look at the results over more than one generation of animals.
The study of animals in psychology is also called comparative psychology.
To understand the effects of attachment on humans, researchers often experimented on animals to see how their behaviour was affected. They look at the formation of early bonds between animal parents and their offspring.
Lorenz and Harlow have carried out leading animal studies of attachment research.
It would be unethical for a researcher to separate an infant from their family, so instead, the research would be conducted on animals. However, animal research is widely criticised as although it is not unethical for humans, it is for animals, and how useful are these findings? But we will get into this a bit later.
Outline the Procedure used in One Study of Animal Attachment – Lorenz's Research (1935)
How was Lorenz's research in animal studies of attachment conducted?
Lorenz first observed imprinting when he was an infant, and a neighbour gave him a newly hatched duckling that followed him everywhere. Later, he studied animals to see if they imprint on a single subject.
Imprinting is the term that describes the biological tendency of infants to form attachments to the first subject they see after birth or hatching.
Lorenz aimed to test imprinting to see if animal infants bond with the first subject they meet. He tested the imprinting theory on some goose eggs in a controlled procedure.
Lorenz set up a classic experiment in which he randomly divided a clutch of goose eggs.
- Half of the eggs hatched with the mother goose in their natural environment.
- Lorenz kept the other half in an incubator, where they would see him as soon as they hatched.
When the eggs hatched from the incubator, Lorenz made a sound imitating a mother goose and then recorded the behaviour of the young.
Lorenz then tagged all the goslings to determine whether they came from the naturally hatched eggs or the incubated eggs. He mixed both groups of goslings and placed them under an upturned box. Lorenz then removed the box and recorded their behaviour. Through this method, he tested whether imprinting had taken place.
Outline the Findings used in One Study of Animal Attachment – Lorenz's Research (1935)
Once he lifted the box, half the goslings ran to their mother goose and the other half to Lorenz.
- The goslings that ran to Lorenz were in the controlled incubator group.
- The goslings that ran to their mother had hatched in her presence.
Lorenz also identified a critical period in which imprinting must occur. Depending on the species, this can be as early as 12-17 hours after hatching (or birth). Lorenz notes that infants will not attach to a mother figure if imprinting does not occur within that time.
The imprinting research suggests that attachment is innate and biologically programmed.
Lorenz also believed that imprinting could not be undone. Once an infant imprints, it cannot imprint on anything else.
Later research supported this theory and showed that imprinting was probably impossible 32 hours after hatching.
The study also found that the strongest imprinting responses occurred between 12 and 7 hours after hatching but could occur as early as one hour after hatching.
Animal Studies of Attachment: Lorenz's Observation of Sexual Imprinting
Lorenz observed that birds imprinted on humans later exhibited courtship behaviour towards humans.
In his 1952 case study, Lorenz described a peacock reared in a zoo's reptile house. The first moving subjects the peacock saw after hatching were giant tortoises.
Once fully grown, this bird would direct courtship behaviour only towards giant tortoises. Lorenz concluded that this meant it had undergone sexual imprinting.
Further research used baby chicks imprinted on a yellow rubber glove that fed them during a critical development period. Later, the chicks attempted to initiate sexual activity with the rubber glove.
This research supports the findings of Lorenz's original 1935 study by suggesting that imprinting is a long-lasting effect. The imprinting process affects the sexual behaviour of the chicks, known as sexual imprinting.
Describe and Evaluate Animal Studies of Attachment – Harlow's Research (1958)
Another prominent ethologist was Harry Harlow, who studied attachment in rhesus monkeys. His research contributed significantly to our understanding of attachment, as monkeys are considered to have similar biology.
Harlow used baby rhesus monkeys he had separated from their biological mothers within hours of birth. He placed these monkeys in a room with 'surrogate' mothers.
- One made of mesh wire provided food.
- The other was made of wood and covered with a soft cloth but provided no food.
Harlow (1958) conducted two similar experiments, the procedure was the same, but they investigated different things.
Experiment one measured how infants responded when scared (if they used the surrogate mother as a safe base) and to determine which surrogate mother they spent more time with. The infants could decide which surrogate mother they approach.
And in the second experiment, Harlow investigated developmental and behavioural differences. The infants were placed into cages with either one of the surrogates, and comparisons with monkeys with normal mothers were compared.
Animal Studies of Attachment: Harlow's Findings (1958)
In the first experiment, the monkeys could choose which mother they wanted to go to. Harlow found that the baby monkeys spent more time with the surrogate 'mother' with the cloth around them, cuddling it, although both mothers supplied the same amount of food. And when frightened, the infants approached the surrogates with the cloth (they used the mother as a safe base).
In the second experiment, the monkeys had no choice of mother. Harlow found that the baby monkeys with the clothed surrogate mother showed healthy and normal emotional attachment despite receiving the same amount of food.
One example is they would come near the surrogate mother and cuddle with her when they feel stressed or threatened.
The monkeys with a surrogate mother made of mesh wire did not behave similarly. When faced with the same level of stress or threat, they threw themselves on the floor, rocked back and forth, and did not seek comfort from their surrogate mother.
In terms of behavioural issues, there were five main differences between surrogate and normal mother groups:
- Timider.
- Difficulty interacting with other monkeys.
- Bullied.
- Difficulty finding partners and mating.
- Females were inadequate monkeys.
As adults, the monkeys deprived of their mothers suffered long-term and irreversible social and emotional damage.
Like Lorenz, Harlow concluded that there is a critical period for forming an attachment. An infant monkey had to be introduced to a mother figure within 90 days to form an attachment. After this time, bonding was no longer possible, and the damage done by early deprivation became irreversible.
Evaluation and Implications of Animal Studies of Attachment
While Lorenz's and Harlow's findings were significant in many ways, they were also subject to considerable evaluation.
Harlow's research yielded valuable practical applications for attachment and the importance of emotional support in early child development. His work influenced John Bowlby, an influential psychologist who studied attachment theory in human children.
Lorenz's and Harlow's research is unethical because of the long-term effects on their animal subjects. In Harlow's case, the monkeys without a mother figure suffered long-term damage.
Limitations of using Animals to Study Attachment in Humans
Later research corroborated Lorenz's findings of imprinting and long-term effects. Monkeys and humans are similar in that they have similar brain structures. From this perspective, Harlow's research will likely help us better understand human behaviour.
Later researchers disproved the theory that imprinting cannot be reversed, finding that the animals could exhibit normal sexual behaviour after joining their species.
Despite the similarities between humans and apes, the cognitive abilities of humans far exceed those of apes, so the research has extrapolation.
Extrapolation is when we generalise the findings from humans to animals.
However, Lorenz's research may not apply to humans because birds are not similar to humans.
Studying animals avoids ethical problems that arise when studying humans. It is unlikely that Lorenz and Harlow would have been able to separate human infants from their mothers in the same way.
Animal studies of attachment: Lorenz (1935) & Harlow (1958) – Key takeaways
- Researchers can use animal studies to learn more about human development and behaviour in psychology. This research is called comparative psychology.
- Animal studies have been used to study attachment. Among the most important studies are those by Konrad Lorenz and Harry Harlow.
- Lorenz studied geese and found that they imprinted on him because he was the first moving subject the goslings encountered.
- Harlow's study of rhesus monkeys found that they form emotional attachments to surrogate mothers that provide comfort.
- Both researchers suggested that this bonding should occur within a critical period of hatching or birth of the animal.
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