Miss Lonelyhearts came from a comfortable background. He had music lessons as a child, and he went to college. Now he lives a cramped, miserable existence in New York City, staying in a rented room and trying to drink his problems away. As a child he noticed something stirring in him whenever he shouted the name of Christ. As an adult he is tormented by despair and religious longing.
Shrike is cruel, like his namesake, the shrike or butcherbird. A shrike keeps its prey impaled on a thorn or a spike, to eat later. As the editor, Shrike toys with Miss Lonelyhearts. Not only does he make a cynical joke out of everything Miss Lonelyhearts does, he also actively tries to cause trouble, as when he reads aloud a letter from the furious Peter Doyle.
Betty lives in New York City but grew up on a farm in Connecticut. She believes Miss Lonelyhearts could be cured of his unhappiness with a different job, and perhaps a simple life and the love of a good woman. Even though Betty is not afraid to tell off Miss Lonelyhearts, she is endlessly forgiving of his cruelty to her.
In Miss Lonelyhearts's eyes Peter Doyle's disability causes him to move awkwardly, with motions "like those of a partially destroyed insect." On the surface Doyle can be good-natured, somebody who will go along to get along. He will make sexual innuendos or self-deprecating jokes to show he is a regular guy. But underneath it all he seethes with resentment and misery.
Miss Lonelyhearts sees Mrs. Doyle as a big woman with legs like "Indian clubs." Mrs. Doyle was abandoned by her baby's father, and she is still not over it. She is scornful of her current husband, whom she regards as "a shrimp of a cripple." She likes to anger him by flirting with other men, but she seems attached to him, too.