What is the theme in White Noise by Don DeLillo?

Identity is a major theme in the book. Jack and his wife Babette deal with their concept of identity in different ways. Frequently, throughout the novel, Jack will define Babette based on how he knows her in the past. For example, if she says something negative, he rebuffs her for breaking character, saying that the Babette he knows is healthy and outgoing and he depends on that Babette. Conversely, Babette will predict how Jack is going to act against Mr. Gray based on his male characteristics, saying that he will act out of primal rage against him. Early in the novel, Jack says that love helps them to develop an identity that is secure enough to be placed under the care of each other. In this way, he admits that their relationship works by letting each member of the family help to give identity to the other members.