What does Postman suggest has contributed to the disappearance of childhood?

Postman argues that the disappearance of childhood is largely due to exposure to adult content through technology. He contends that with the advent of television and other forms of media, children are increasingly exposed to themes and imagery that were once reserved for adults. This exposure accelerates the loss of innocence and the delineation between childhood and adult experiences.

Postman emphasizes that traditional markers of childhood, such as play and imagination, have diminished as children are confronted with the complexities of adult life far earlier than previous generations. The omnipresence of media, including violent imagery, sexual content, and complex societal issues, has effectively blurred the lines between childhood and adulthood, shaping children's understanding of the world in a way that differs significantly from earlier eras when childhood was more clearly defined and protected.

In contrast, concepts such as increased schooling, changes in family structure, or a decreased population of children do not directly address the central theme of media influence and the resulting shift in childhood experience as highlighted by Postman.