Animal studies of attachment

• Why should we use animal studies for psychological research into attachment?

  • According to Charles Darwin, humans have descended from animal ancestors. Moreover, humans retain many biological and psychological characteristics from their animal ancestors.
  • They can be used to look at the formation of early bonds between non-human parents and their offspring.
• Lorenz Procedure

  • Split a large clutch of Greylag goose eggs into 2 batches.
  • One batch hatched naturally with the mother
  • Second batch hatched in an incubator with Lorenz, making sure that he was the first moving object the Goslings encountered.
  • Behaviour of the goslings was recorded
  • Lorenz marked the goslings, so he knew which ones hatched naturally and which hatched in the incubators.
  • Both groups let out together, so their behaviour could be recorded to test the effect of imprinting.
• Findings of Lorenz study

  • After birth, the naturally hatched baby goslings followed their mother, whilst the incubator goslings followed Lorenz.
  • Lorenz proposed the effects of imprinting are long lasting and irreversible.
  • Imprinting occurs during a short period after birth- critical period
• What can we conclude from Lorenz study?

  Imprinting is an innate mechanism which species are biologically programmed to do as soon as they see the first moving object.
• Imprinting

  • An innate readiness to develop a strong bond with the mother which takes place during a specific time in development (first few hours) to the first moving thing it sees upon being born.
• Critical period

  A biologically determined period of time, during which certain characteristics can develop. Such developments would not be possible outside of this time period.
• Sexual imprinting


  Early imprinting, affects later mate preferences- animals would choose a mate who is similar to object/species they had imprinted on.
• Research support for sexual imprinting

  • Lorenz
  • Relationship between imprinting and adult mate preferences
  • Imprinting will lead to courtship behaviour later being displayed
  • Lorenz, reported a peacock being reared in a reptile house of a zoo.
  • Imprinted on a giant tortoise
  • Later the peacock would show courtship behaviour towards giant tortoises.
• Supporting evidence- Lorenz

  • Guilton, demonstrated that leghorn chickens exposed to yellow rubber gloves for feeding them during the first few weeks became imprinted on the gloves.
  • This evidence supports the view that young animals are not born with a predisposition to imprint on a specific type of object, but probably on any moving thing that is present during the critical window of development.
  • This suggests that imprinting is innate which supports the findings proposed by Lorenz.
• Criticisms of Lorenz research

  • Guilton et al, found that he could reverse the effects of imprinting in chickens who initially tried to to mate with rubber gloves. This can be done by spending time with their own species which enabled them to engage in normal sexual behaviour.
  • Suggests imprinting is not permanent as Lorenz suggested, and there is a possibility for the imprinting to be reversed through interaction with their own species.
  • Contradictory evidence surrounding Lorenz’s research is not reliable as the findings are not consistent.
• Lacks generalisability

  • For example, Lorenz research was focused on the influence of imprinting in birds. Some differences are that mammalian mothers show more emotional attachment to their young compared to birds.
  • This is because humans and animals are physiologically different. The way a human infant develops an attachment with their primary caregiver could be very different to the way geese form attachments with their primary caregiver.
  • Therefore it is not appropriate to attempt to extrapolate the findings by Lorenz.
• Procedure in harlow’s monkey study

  • 2 types of surrogate mothers were constructed- wired/soft-clothed
  • 8 Rhesus monkeys- 4 in each 2 conditions
  • A cage containing a wire mother producing milk, soft clothed mother producing no milk.
  • A cage containing a wire mother producing no milk and a soft clothed mother producing milk.
  • Studied for 165days
  • Amount of time with each mother was recorded.
  • Monkeys frightened with loud noises to test for preference when stressed.
• Findings from Harlow’s monkey study

  • All monkeys spent most of their time with soft-clothed mother, regardless of whether they had a feeding bottle.
  • Monkeys fed from wire mother only spent a short amount of time getting food and returned to soft-clothed mother
  • When frightened, all monkeys remained with soft-clothed monkey.
• What can we conclude from Harlow’s monkey study?

  • Suggests that Rhesus monkeys have an innate, unlearned need for contact comfort, suggesting that attachment concerns emotional security more than food.
• Long-lasting effects of Harlow’s study

  • Motherless monkeys, even those with contact comfort, developed abnormally.
  • Both socially (froze and fled when approached by other monkeys) and sexually (did not show normal mating behaviour)
• What is the critical period when it comes to forming attachments in monkeys?

  • 90 days
  • After this attachment was impossible and damage from early deprivation became irreversible
• Theoretical value- mother-infant attachment

  • For instance, Harlow proposed that attachment does not develop as a result of being fed by a mother figure, but as a result of contact comfort.
  • Harlow’s findings have informed us about the important of early attachment and how vital they are in influencing social development. His study has suggested what role contact comfort has to play, that is to ensure the caregiver provides warmth and emotional security. The study emphasised that contact comfort is essential.
  • Harlow’s study has played a role in understanding attachment formation.
• Practical value

  • Howe, reports that Harlow’s research has helped social workers understand risk factors in child neglect and abuse and so intervene to prevent it. In addition, it has influenced the care of captive monkeys, we now understand the importance of attachment figures.
  • Helps social workers and clinical psychologists employ strategies to ensure their development is not impaired due to neglect.
  • Can be used to make practical changes in allowing healthy attachments to form.
• Ethical issues

  • Monkeys were taken from their natural mothers very soon after birth and suffered a great deal of distress being reared in cages and social isolation.
  • Monkeys were subjected to psychological harm as they experienced separation from their biological mother. Guidelines have been violates as the monkeys did experience long-lasting effects e.g socially and sexually abnormal.
  • Consequently, Harlow’s research may not have been justified due to breaching ethical guidelines