Harlow’s research involving baby monkeys being raised in isolation with two surrogate mothers made out of wire or cloth found that the monkeys later grew up
with social and emotional disturbances whereby they were less sociable, less likely to breed, and more aggressive. strength of research into the
influence of early attachment on later relationships- shows how if an infant receives no stimulation or sensitivity from their caregiver i.e. have a poor/non-existent attachment, it can adversely affect their later relationships.