Which character's identity does Vincent adopt to pass as a valid?

Vincent adopts Jerome's identity to pass as a valid in the society depicted in GATTACA. This choice is pivotal for several reasons. Jerome is a genetically superior individual, designed to be the ideal human, which allows Vincent to disguise himself successfully and avoid the societal discrimination faced by those born with genetic imperfections, known as "in-valids." By using Jerome's identity, Vincent not only takes on his genetic credentials but also his physical characteristics, thanks to the use of advanced technology that allows Vincent to change his appearance, such as through blood and urine samples. By living as Jerome, Vincent can access opportunities that would otherwise be denied to him, emphasizing the film's themes of identity, ambition, and the societal pressures surrounding genetic determinism.