The Gen X childhood coincided with the sexual revolution of the 1960s to 1980s, which Susan Gregory Thomas described in her book "In Spite of Everything" as confusing and frightening for children in cases where a parent would bring new sexual partners into their home. Thomas also discussed how divorce was different during the Gen X childhood, with the child having a limited or severed relationship with one parent following divorce, often the father, due to differing societal and legal expectations. In the 1970s, only nine U.S. states allowed for joint custody of children, which has since been adopted by all 50 states following a push for joint custody during the mid-1980s. "Kramer vs. Kramer", a 1979 American legal drama based on Avery Corman's best-selling novel, came to epitomize the struggle for child custody and the demise of the traditional nuclear family.