Animal studies of attachment

• Lorenz (1952)'s procedure:


  Lorenz randomly divided a large clutch of goose eggs. One half were hatched with the mother goose in their natural environment. The other half hatched in an incubator where the first moving object they saw was Lorenz. Mixed all goslings together to see whom they would follow. Lorenz also observed birds and their later courtship behaviour.
• Lorenz (1952)'s findings:

  Incubator group followed Lorenz, control group followed the mother. Lorenz identified a critical period in which imprinting needs to take place, eg. a few hours after hatching. If imprinting did not occur within that time, chicks did not attach themselves to the mother figure. Sexual imprinting also occurs whereby the birds acquire a template of the desirable characteristics required in a mate.
• AO3 - Lorenz - Support for the concept of imprinting:


  Regolin and Vallortigara (1995) exposed chicks to simple shape-combinations that moved. When shown a range of moving shapes the chicks followed these in preference to other shapes. This suggests that young animals are born with an innate mechanism to imprint on a moving object.
• AO3 - Lorenz - generalising from birds to humans:


  The mammalian attachment system is quite different from imprinting in birds. For example, mammalian mothers show more emotional attachment to their young. This means that it may not be appropriate to generalise Lorenz's ideas about imprinting to humans.
• Harlow (1958)'s procedure:


  Harlow reared 16 rhesus monkeys with two wire model 'mothers'. In condition 1, milk was dispensed by the plain-wire 'mother'. In condition 2, milk was dispensed by the cloth-covered 'mother'. To measure attachment-like behaviour, Harlow observed how the monkeys reacted when placed in frightening situations, eg. a noisy mechanical bear in the environment. Harlow also continued to study monkeys who had been deprived of their 'real' mother into adulthood.
• Harlow (1958)'s findings:


  Baby monkeys cuddled the cloth-covered mother in preference to the plain-wire mother regardless of which dispensed milk. This suggests that contact comfort was of more importance than food when it came to attachment behaviour. The monkeys sought comfort from the cloth-covered mother when frightened. As adults, the monkeys who had been deprived of their real mothers suffered severe consequences - they were more aggressive, less sociable and less skilled in mating than other monkeys.
• AO3 - Harlow - real-world value:

  It has helped social workers understand risk factors in child abuse and thus intervene to prevent it. We also now understand the importance of attachment figures for baby monkeys in zoos and breeding programmes. This means that Harlow's research has benefitted both animals and humans.
• AO3 - Harlow - Ethical issues:

  Harlow's procedures caused severe long-term distress to his monkey participants. However, his findings and conclusions have important theoretical and practical applications. This suggests that, in spite of its benefits, Harlow's research perhaps should not have been carried out.