Faulkner tells us that Jason is the last of the Compsons because he is a bachelor who will never marry. Jason is the type of person who exists solely for himself and believes that the entire world should exist along the lines that he thinks are right. He denies any allegiance to, or love for, anyone except himself.
Jason delights in acts of perversity. He enjoys burning two free passes to a show simply to torment a fourteen-year-old black boy. He also spends time thinking of perverse ways to torment Miss Quentin, his niece, and Dilsey, his mother's cook. He comes in late for work, hoping that Earl, his employer, will complain so that he can then say something nasty.
Jason's success in life is due to the fact that he feels no love for anyone. Whereas other people would be proud of their ancestry, Jason completely rejects all blood kin or all connections with everything in the past. He has a monomania that allows him to hate his sister, Caddy, with as much viciousness in 1928 as he did in 1910. He can carry a grudge and hatred longer than most people can remember. During his entire section, he never speaks a kind or decent word to anyone. To him, his duplicity and hypocritical actions are merely simple forms of behavior that are necessary for survival.
Jason has worked out a complicated scheme whereby he cheats his mother out of a large sum of money and makes her think that he is a self-sacrificing, hard-working, honest man. He respects his cheap whore that he keeps in Memphis, but he delights in beating his niece for going out with men. He beats Miss Quentin not because he feels that what she does is immoral, but because he feels that what she does will make a fool of him. Furthermore, if he ever loses control of her, the monthly check that he steals from Caddy will be lost to him.
Jason is likewise the only one whom Mrs. Compson loves. Knowing her character as we do, this is probably one of Jason's worst attributes; that is, he can evoke the love of only a sick, neurotic woman. The other children need and want Mrs. Compson's love, but Jason neither wants it nor returns it. He does, however, use it in order to gain the power of attorney from her and thereby cheat her out of large sums of money.
Jason is the most amoral, materialistic, and mean person in the novel, a man who delights in perverseness for its own sake.