We all became very aware after the fall of the repressive Romanian regime just how badly affected children become when they are abandoned of proper loving care. Pictures of Romanian orphanages showed the damaged young children engaged in repetitive motions in cots.
So this real situation re-introduces issues in psychology about the function and loss of a primary caregiver and other caregivers.
The starting point is Freud with Erickson, but then with a change of perspective and moving towards a more evidential and behaviourist method. This tells something about process and method in psychology.