(Harlow, 1958; Harlow 8c Harlow, 1965). (Much later, an evolutionary approach to
attachment and pair bonding in mammals was outlined by Fraley, Brumbaugh 8c Marks,
2005.) This included deprivation of contact with their mothers. A monkey mother provides
more than contact, food, rocking and warmth: she is the first link in the chain of
the baby's experience of socialisation. Harlow's investigation was extended to babies who
were totally isolated from contact with any living being for up to 12 months. Such long
periods of solitary confinement had drastic consequences. The infant monkeys would
sometimes huddle in a corner, rock back and forth repetitively, and bite themselves.
When later exposed to normal peers, they did not enter into the rough-and-tumble play
of the others, and failed to defend themselves from attack. As adults, they were sexually
incompetent.