11. Harlow monkeys
American psychologist Harry Harlow studied nature of Rhesus macaque attachments during the 50s. He isolated child macaques from their mothers and peers and placed into the cage with “surrogate mother” made out of wire mesh and towel. Soon macaques` feeling of attachment to real mothers, that were not present, was transformed to artificial one. The experiment is considered to have certain investment into science development however it brought a lot of critique from society.