Suburbia
Suburbia is a symbol of what Paul and Elaine strive for the most as well as what they desire the least. Normalcy in suburbia represented by a spacious house, a big yard, friendly neighbors and that entire sense of community is what they have been working for as the realization of an economic dream, but in that process it has served to become what they fear the most: losing all contact with their individuality, no matter how very deeply flawed that individuality may be.
The Nielsens
The Nielsens are both perfectly named and ironically named representatives of supposed idealized suburbanite dreams come true. That they are clearly intended as symbolic figures can be gleaned from having the same name as the once-famous company responsible for deciding what were the most popular television shows throughout all of America by sampling a notoriously small percentage. The Nielsen ratings were perhaps the most famous embodiment of statistical analysis in America and the implicit assumption was that any show which received a large enough audience to make into the top ten was by definition a representative of what every type of American wanted to watch most. Just as the ratings with which they share their name contained a certain creepy factor in its data assumptions, so too is the Nielsen family just a little too representatively perfect to be entirely trustworthy.
Sex
Sex is the central symbol of the inability to fully express individuality or made meaningful contact within the world of suburban nightmare fuel. Both Paul and Elaine engage in sometimes extreme intercourse with each other as well as others in an attempt just to feel something or enjoy breaking from the norm. But even when the Mrs. Nielsen displays a surprisingly kinky side herself, it winds up being not so much tangibly exciting as symbolically peculiar.
The Torched House
The burning and ransacking of the house by Paul and Elaine is intended to be the act which finally sets them free. By the end, however, it has clearly become a symbol for what was keeping whatever life they had together. Once the house is burned down, the family comes tears apart and husband and wife can no longer cling to their roles as father and mother as a means of lending their lives meaning.
Sammy
Aside from suburbia and its numbing effects on both individuality and finding a true sense of community, the central symbol of the novel turns out to be Sammy. The story of this dysfunctional family begins with a crucible of fire intent to purify, but ultimately it requires a sacrificial lamb to provide any hope for redemption.
