Animal studies of attachment - Lorenz and Harlow

Lorenz key study method

Lorenz (1935) divided gosling eggs into 2 groups. One group was left with natural mother and the others placed in an incubator. The incubator group imprinted on Lorenz (the first moving thing they saw). When both the natural mother and Lorenz present the incubator group followed Lorenz and natural group followed mother.

Lorenz key study findings

the incubator group showed no recognition of their natural mother. Lorenz (1935) noted that imprinting is restricted to a brief period in a young animal’s life (critical period). If a young animal is not exposed to a moving object during the critical period they will not imprint. Suggests animals can imprint on moving objects seen in their first 2 days. Imprinting is irreversible and long-lasting, one of the goose who imprinted on Lorenz (Martina) slept on his bed every night. Found sexual imprinting - animals (especially birds) will choose to mate with the same kind of object they imprinted on (imprint on rubber gloves, try to mate with rubber gloves)

Evaluation of Lorenz’s research - Other studies have supported imprinting in animals

advantage - other studies have supported imprinting in animals. Guiton (1966) found leghorn chicks exposed to yellow rubber gloves while being fed, imprinted on the gloves. Supports animals imprint on any type of moving object present during critical period. Male chicks tried to mate with gloves. Suggests early imprinting is linked to later reproductive behaviour

Evaluation of Lorenz’s research - Not fully generalisable to humans

disadvantage - not fully generalise to humans (curlews do not imprint of humans)

Evaluation of Lorenz’s research - Imprinting is actually reversible

disadvantage - Guiton (1966) found he could reverse the imprinting in chickens that tried to mate with yellow rubber gloves. After spending time with own species, they were able to engage in normal sexual behaviour with other chickens. Suggests imprinting is not very different from other types of learning and its reversible unlike Lorenz suggested.

Harlow key study method

8 monkeys were studied for 165 days. Condition 1: 4 monkeys had a cloth-covered mother with a milk bottle and a wire mother without a milk bottle. Condition 2: 4 monkeys had a cloth-covered mother without a milk bottle and a wire mother with a milk bottle. Amount of time each infant spent with each mother was measured. Monkey reactions when frightened by mechanical teddy bear were observed. The 2 mothers heads were different

Harlow key study findings

all monkeys spent most of their time with the cloth mother regardless if it had the feeding bottle. monkeys with bottle on wire mother only fed for a short time before returning to the cloth mother. when frightened all monkeys clung to cloth mother. when playing with new objects kept one foot on mother for reassurance. motherless monkeys were socially and sexually abnormal. Harlow (1959) found this had a critical period. Monkey with more than 6 months with a wire mother couldn’t recover.

imprinting defintion

innate readiness to develop a strong bond with mother that occurs during a critical period soon after birth. if it doesn’t occur during critical period it probably won’t happen

evaluation of Harlow’s research - Confounding variable

disadvantage - the 2 stimulus objects varied in heads acting as a confounding variable because it varied systematically with the independent variable (cloth/wire mother). its possible the reason the monkeys preferred the cloth mother is because it had a more realistic head. Therefore, Harlow’s (1959) conclusions lack internal validity

evaluation of Harlow’s research - Results cannot be generalised to humans

disadvantage - It is questionable whether findings and conclusions can be generalised and applied to complex human behaviours. It is unlikely that observations of goslings following a researcher or rhesus monkeys clinging to cloth-covered wire models reflects the emotional connections and interaction that characterises human attachments. Suggests we should always seek confirmation of a behaviour by looking a research with humans. COUNTER - Schaffer and Emerson’s found that infants are not most attached to the person who fed them suggesting animals have greater needs than just food

evaluation of Harlow’s research - Humans and monkeys are similar

advantage - Green (1994) states that, on a biological level at least, all mammals (including rhesus monkeys) have the same brain structure as humans; the only differences relates to size and the number of connections in the brain. Suggests animal studies can be generalised accurately to human behaviour.

evaluation of Harlow’s research - Important practical applications

advantage - Harlow’s research has profound implications for childcare. Due to the impact of early experiences on long-term development, it is vital that all of children’s needs are catered for; taking care of a child’s physical needs alone is not sufficient.

evaluation of Harlow’s research - Animal research is unethical

disadvantage - It could be argued that animals have a right not to be researched/ harmed. The pursuit of academic conclusions for human benefits could be seen as detrimental to non-human species as Harlow’s (1959) study created lasting emotional harm (monkeys found it difficult to form relationships). COUNTER - could be argued that the benefits of the findings outweigh the costs to the animals as our understanding of attachment is greater. this can be used to offer better care for human/primate infants. Also this would not happen today due to ethical guidelines.

attachment definition

a strong emotional bond between and infant and its primary caregiver, important for survival and future relationships