Quote 58
At the Abnegation table, we sit quietly and wait. Faction customs dictate even idle behavior and supersede individual preference. I doubt all the Erudite want to study all the time, or that every Candor enjoys a lively debate, but they can't defy the norms of their factions any more than I can. (2.7)
Everyone in a faction does the same things because they're in that faction. And yet Tris recognizes the possible separation between the "individual preference" and "Faction customs." Is Tris the only one who feels like making a non-faction choice? (Probably not, but it can feel like that sometimes.)
Quote 59
"Beatrice," he says, looking sternly into my eyes. "We should think of our family." There is an edge to his voice. "But. But we must also think of ourselves."(4.64)
Tris isn't the only one who wants to express her individual choices against the faction norms (see above). Even Caleb, the perfect Abnegation, does something very non-Abnegation here. And we know this is a big issue because Tris keeps breaking in to tell us it's a big issue: Caleb's eyes are stern, his voice has an edge. If this were just a boring line of dialogue, Tris probably wouldn't be noticing all these little physical clues.
Quote 60
If I help her, Eric would make my fate the same as hers. Will I let her fall to her death, or will I resign myself to being factionless? What's worse: to be idle while someone dies, or to be exiled and empty-handed? (9.80)
Even after the big decision about what faction to be in, Tris is left with dozens of other choices about how she wants to act. Here's one of the most striking choices. And what's striking about it is that Tris doesn't choose the action-hero "do the right thing no matter the cost" choice. Instead, she chooses to let her friend dangle for a while. Yikes.