Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Sincere, Sympathetic
This is Lennie's world and we're just living in it (okay, we're reading through it, but whatever). And since Lennie is earnestly trying to get her bearings following the devastating death of her older sister, the tone for this book is sincere, evoking sympathy for the main character from even the hardest hearted readers. After all, as Lennie makes her way through the terrible terrain of grief, we're privy to her thought process in minute detail. For instance:
I see in the movie of Toby's words how happy she would have been, and suddenly, I just don't know where all that happiness, her happiness, and ours, will go now, and I start to cry, and then Toby's face is above mine and his tears are falling onto my cheeks until I don't know whose are whose, just know that all that happiness is gone, and that we are kissing again. (10.63)
The long sentence moves from thought to thought, winding its ways through Lennie's complex feelings so we really feel how Lennie moves in the direction of kissing. And when we do, we understand she's not a manipulative demon, but instead more like a girl who doesn't know what to do and feels completely overwhelmed and out of control. Thanks to Lennie's sincerity, our sympathy is rock solid no matter how much she fumbles.