I've heard about an experiment from one of my teachers that took place in Russia some time ago. It involved a theory about human babies. The theory argued that human infants are not only dependent on it's mother for food and protection but equally important is their touch and presence. Absent of the latter two, it was theorized that human babies would not be able to survive.

To test this theory, scientist took babies and completely cut them off from any form of human contact. They made sure that the babies were fed and kept warm. They wanted everything that a baby needed to be taken care of without any human contact.

The results were suprising. One by one, the babies passed away. There was no physical reason why they didn't survive only that the human infant needs human contact just as much as it needs food and shelter to survive

I was intrigued when I heard of this story. I haven't been able to pull up any records of such an experiment. It sounds like folklore to me but I will see if anyting shows up.