The theme of the story is that without human interaction, people become soulless monsters.
In this story, the people have given too much control of their lives to technology, and they pay the price. This is a common theme in Bradbury’s stories. Technology takes the place of human interaction, and in fact humanity, and the result is chaos and disaster.
The family in this story has purchased a HappyLife home, which is an ironic title because their home is anything but happy. The family is completely disconnected from their children. They do not know them at all, and have actually hired a psychologist to come and tell them what is going on with their own kids. What is going on is that they have a high-tech nursery taking over their function as parents, and the house bathes and nurses their kids for them, and they do nothing.
The mother, Lydia, feels as if she has been replaced with technology.
I feel like I don't belong here. The house is wife and mother now, and nursemaid. Can I compete with an African veldt? Can I give a bath and scrub the children as efficiently or quickly as the automatic scrub bath can?
She knows that something is wrong, but not the extent of it. What she doesn’t understand is that while a house can give a child a bath, it cannot provide a loving embrace or tell a child a story. A house does not have a soul. Without a soul, a child becomes a sociopath. This is exactly what happened to these children.
The nursery reflects what is in the children’s soul. What is in the children’s soul? Murder!
Remarkable how the nursery caught the telepathic emanations of the children's minds and created life to fill their every desire. The children thought lions, and there were lions. The children thought zebras, and there were zebras. Sun—sun. Giraffes—giraffes. Death and death.
George, the father, feels that his children are awfully young to be thinking about death. He doesn’t realize they are planning his murder. His children are cold-blooded killers. They spend all of their time in the nursery. They are obsessed with the nursery. They are dependent on the nursery, and the house, and all of its caregiving technology. What do they need parents for? What kind of relationship do they have with their parents? When have they had time to develop when, since they spend all of their time with the house? Punishing them by taking the nursery away only makes things worse, because the nursery is what they live for.
Technology cannot replace human interaction. It cannot replace our humanity. All children who grow up with iPads in their hands instead of Mommy reading them a book will not grow up to be serial killers, but still, it is food for thought. We need our interaction with each other to make us human.