How did the monkeys behave when they were adults

• Harlow also investigated the monkeys who had been deprived of a ‘real’ mother into adulthood to see if the early maternal deprivation had a permanent effect
• The researchers found severe consequences
• The monkeys didn’t develop normal social behaviour
• They were aggressive and less sociable that other monkeys
• When the monkeys became mothers some of them would neglect their young, some attacked their offspring, eventually killing them in some cases
• Harlow concluded that there was a critical period of attachment formation (90 days) and after this the damage Done by early deprivation became irreversible