Several people who have analyzed Genie's linguistic development have compared it to historical accounts of children with delayed language acquisition, including records of language deprivation experiments of Psamtik I, King James IV of Scotland, and Holy Roman Emperor Frederick II. Linguists have especially noted the similarities between Genie's case study and the testing of Victor of Aveyron. The scientists acknowledged the impact these cases had on their research and testing methods, and linguists and historians have cited Genie's case as the impetus for reanalysis of the case study on Victor. Both the research team and outside analyses especially contrasted Genie and a case in the 1950s of a girl known by the name Isabella, who had been abused and isolated from all speech until the age of 6 but within a year of receiving therapy spoke using vocabulary and grammar typical of someone her age. Author Justin Leiber compared Genie to Helen Keller, particularly noting the differences between the language instruction each received.
