Years spent hunting for sibling rivalry stories make me think a lot of twin-focused narratives miss the point by making everything symmetrical. 'The Thirteenth Tale' by Diane Setterfield is probably my benchmark for getting the unsettling, almost gothic tension right; it’s less about physical competition and more about the haunting psychological echo one twin leaves behind.
Other books seem to treat twinship as a cheap plot device. 'We Were Liars' involves twins, but the rivalry feels secondary to the overall family mystery, which actually works better for me—it’s not the sole defining trait.
A recent read that surprised me was 'The Silent Patient'—not explicitly about twins, but the sibling dynamic there has a corrosive, slow-burn rivalry that mirrors a lot of twin tropes without the cliché mirror imagery. Sometimes the best explorations come from stories that aren’t even trying to check that box.
The 'Sweet Valley High' series? Pure nostalgic fun, but the rivalry there is so cartoonish it loops back to being entertaining. For a genuine, messy, adult take, I’d point people toward 'The Dutch House' by Ann Patchett. The central relationship between Danny and Maeve isn’t twin, but the lifelong resentments and loyalties capture a truth that most twin-specific fiction strives for.