Animal studies

Animal studies

1. Lorenz (1935)

   • Divided gossling eggs into 2 groups
   • One group wiht mother, other group incubated and hatched looking at Lorenz
   • Group 2 started following Lorenz
   • Marked group 2 eggs and put them back wiht group1 + mother
   • What he found
     • Lorenz's gosslings showed no sign of recgonition of mother
     • Imprinting has to take place in a critical period ( up to 2 days)
       • If imprinting does not happen in this window, then it will never happen
     • Imprinting is irreversible and long lasting
     • has impact on mate preferences (sexual imprinting)
       • Animals (mainly birds) choose a mate similar to the object they imprinted on
   • Evaluation

2. Harry harlow (1959)

   • Demonstrated that attachment is not based on the feeding bond (learning theory)
   • Created two wire 'mother' monkeys, one with soft cloth and other wire bare wire.
   • Monkeys studied for 165 days
   • For 4 monkeys milk bottle was on cloth covered monkey and other 4 monkeys the milk was on the wire monkey
     • Also observed monkeys reactions to being scared by a mechanical teddy bear
   • What he found
     • All 8 monkeys spent most of their time with the cloth covered monkey whether or not it had the milk bottle
     • Monkeys used the wire mother for only enough time to feed then return to cloth monkey.
     • When frightened all monkeys went to the cloth mother
     • Used mother for reassurance by having feet to feet contact when playing with new objects.
     • These findings suggest that infants form attachments with the person offering comfort rather than who feeds them
   • long lasting effects
     • Monkeys grew up socially abnormal and sexually abnormal
     • Found critiical period for these effects
       • more than 6 months with wire monkey meant they could not recover from
         • However they could recover if spent time with peers (other monkeys) before they were 3 months old.