Others confide in Ponyboy because he is sensitive and he listens to them without judging.
Ponyboy describes himself as “different.” When he watches movies he likes to “get into them and live them with the actors” (Ch. 1). He also likes to read books. He thinks about things, and he is reflective about issues of social class. He doesn’t just identify with being a greaser, he thinks about what makes him one.
When Pony meets Cherry, she identifies him as not looking “the type.” She treats him and Johnny politely, and also says that the two of them “don’t look mean (Ch. 2).
"No," Cherry said slowly, looking at me carefully, "not innocent. You've seen too much to be innocent. Just not ... dirty." (Ch. 2)
Cherry has sized Pony up and realized that even though he comes from a dangerous neighborhood, he is not a “hood” as the girl in biology class stereotyped him. He is just a poor kid whose parents died, whose oldest brother is trying to keep the family together. He does hang out with people like Dallas Winston, who is rough, but party for protection. He did not contribute to the dirty talk or harassing the girls. As Pony says, that is just the way gangs work.
When you're a gang, you stick up for the members. If you don't stick up for them, stick together, make like brothers, it isn't a gang any more. It's a pack. (Ch. 2)
Cherry gets this, as a member of a gang herself. She may have money, but as a Soc she has seen her Soc friends do things she does not approve of either. When Cherry notes to Pony that they see the same sunsets, she is realizing that Pony is deep enough to see beyond social class to see that things really are tough all over.
Johnny also confides on Pony for many of the same reasons as Cherry does. He knows that Pony listens, and Pony is smart. When they run away together and hide out in the church, they discuss school and grades, Robert Frost and Gone with the Wind, and Pony treats Johnny like an equal. Even though Johnny is not in advanced classes like Pony, he still can discuss how he feels about literature.
I guess his teachers thought he was just plain dumb. But he wasn't. He was just a little slow to get things, and he liked to explore things once he did get them. (Ch. 5)
Johnny has had a hard life, coming from a violent home and having been jumped by the Socs. He was further traumatized by having killed Bob, something a sensitive kid like Johnny never meant to do. Pony understood these things about him, and Johnny understood that. This is why he asked Pony to “stay gold,” or remain good and not become a hood and turn to gang life.
Randy also understood that a life of gangs and rumbles was not for Pony. When he said he was going to stay home from the rumble because there had been enough killing, and he did not want to avenge Bob’s death, he saw a kindred spirit in Pony. He knew about the fire and felt that anyone who had tried to save kids could not be all bad.
“… I'm a Soc. You get a little money and the whole world hates you." (Ch. 7)
Randy confides in Pony because he feels trapped. He realizes that the stereotypes he held of greasers were ridiculous, and they are trapped in a never-ending cycle. As he said, the killing will never stop. He doesn’t really accomplish anything from talking to Ponyboy except confirming his suspicions that not all greasers are crazed killers.
Ponyboy’s sensitivity is at the center of the story, and characters gravitate toward him as a sounding board. His honesty and grace help them to face their own fears and doubts, and although he lacks confidence in himself, his thoughtfulness sometimes inspires it in others.