It can support Bowlby's maternal deprivation hypothesis as Harlow&Harlow found that the monkey's who were deprived of their mother's had problems interacting with other monkey's later in life. This supports Bowlby's idea of an internal working model which is a cognitive repsresentation of relationships based on the first maternal relationship you had (so the monkeys wouldn't have had very good relationships with their mothers).
There are two research findings that challenge the learning theory of attachment. The first research finding was concluded by Harlow’s study in 1959 entitled ‘The Origins of Love’ where he noticed that young monkeys who were kept on their own in cages, became quite distressed when their caged were being cleaned, as they had become attached to the ‘sanitary pads’ lining the base of the cage, having used these as a ‘security blanket’. Harlow created two wire monkey mothers and attached them to the cage – one was covered in soft cloth and the other had a bottle of milk attached to it. The expected result according to learning theory was for the monkeys to become attached to the lactating mother, who would have satisfied the young monkeys’ hunger drive. In reality, the monkeys became attached to the cloth covered monkey as it provided a sense of protection’ when they were frightened. The first limitation of learning theory here is that contact comfort is more important than food.
I just copied and pasted this from one of my homeworks. Hope it helps =P
The study shows attachments don't happen because of food but because of comfort. Monkeys spent more time with the wired mother who was covered in cloth that offered comfort than the mother who offered food but was only made of wire. Monkeys spent a lot of their time with the cloth mother in times of high distress.