Although they are both Greasers, Pony and Johnny come from different family backgounds.
Pony's parents were killed in an accident months before the start of the plot, but the legacy of love lives on in the boys. Ponyboy says that his mom was "beautiful and golden, like Soda, and wise and firm, like Darry." Even in their physical absence, the brothers stay together following the absence. Pony and Darry struggle to exist in the same space without their parents in the first part of the book, but they forge a new relationship following the incident at the church. Soda and Pony are close for the duration of the novel. Pony has a solid support system in his brothers, and he was raised by loving parents whom he misses.
Johnny is not so fortunate. He has been abused by his parents both physically and emotionally, and Ponyboy describes him as looking like a puppy that has been kicked too many times. When Johnny is in the hospital, he asks if his mother asked about him. (She didn't.) When a nurse comes in to tell Johnny that his mother has arrived, Johnny turns white and passes out. She verbally attacks Pony and Two-Bit in the hall, telling them that they are to blame for the accident; they refuse to let her see Johnny.
The contrast proves that socioeconomic status does not equalize people, and that there are always variances of support in all family situations.