3.4 Animal studies

3.4 Animal studies

1. Harlow (1958)

   • Observed the importance of contact comfort using rhesus monkeys.
   • Procedure: Monkeys were separated from their mothers and raised in isolation cages exposed to two mother figures. One was a wire mother while the other a cloth covered mother for comfort. 4 of the monkeys were exposed to the cloth mother having a milk bottle while the other 4 were exposed to wire with milk.
     • Findings: Monkeys, when presented with a frightening situation, cuddled the cloth covered monkey in preference to the plain wire regardless of which dispensed the milk. Showed that contact comfort was more important than food when it comes to attachment.
     • Critical period for attachment of 90 days.
   • Evaluation
     • Strengths:
       • Real life application. Helped social workers understand the risks of lack of bonding experience.
     • Weaknesses:
       • Lack of generalisability. Rhesus monkeys are more similar to humans than Lorenz's geese, but still humans have a more complex brain.
       • Ethical issues. Caused long term distress to these monkeys.
   • Later followed these monkeys into adulthood to see the effects of maternal deprivation. Found severe consequences, monkeys reared by plain wire mother were the most dysfunctional. All the monkeys did not develop normal social skills, becoming more aggressive and less sociable. Also were unskilled at mating but if they had young, would typically attack and kill them.

2. Lorenz (1952)

   • Observed the phenomenon of imprinting using ducklings.
   • Procedure: Divided a group of goose eggs into those which would be hatched with the mother goose, and those that would be hatched with Lorenz in an incubator.
     • Findings: Incubator group followed Lorenz around, and those born with the mother followed her around. When the two groups were mixed, the incubator ones continued to follow Lorenz. He identified a critical period for imprinting which varies from species to species.
   • Sexual imprinting was also investigated, which showed that if a bird was imprinted on a human, then it would end up showed courting behaviours towards humans. E.G a peacock which was reared in a reptile house, ended up trying to mate with exclusively tortoises.
   • Evaluation
     • Strengths:
       • Supporting research. A study by Regolin and Vallortigara showed that if exposed to simple moving shape combinations, chicks would follow the original closely. Supports the view that animals have an innate mechanism to imprint on a moving object during the critical period.
     • Weaknesses:
       • Cant generalise between birds and humans. Lorenz's study focuses on birds which have different attachment mechanisms to humans. Not a good idea to generalise his findings to humans.