How we cite our quotes:
How can I not trust another human completely? We're family—both part of the brotherhood of extinction. (4.97)
Wanda's species, they all get along perfectly with one another. The human race? Not so much. Melanie has to be fearful when she encounters Jared for the first time. Even though she's human, and there aren't many of them left, she still has to be wary.
"Human hosts need interaction." (6.17)
The souls take on a lot of traits from their hosts. With humans, it's the need to socialize. On other planets, we get the feeling that Wanda and her kind lived a mostly solitary existence. But on Earth, they're having to actually interact with one another or face betrayal by their own bodies. Humans have a biological need to live in communities, and the aliens have to obey it.
My first language [...] had no word for betrayal or traitor. Or even loyalty—because without the existence of an opposite, the concept had no meaning. (9.115)
Wanderer's species exists in perfect harmony. It's sickeningly sweet. Only when they end up in the bodies of lying, cheating humans do they start to learn the meanings of these words and feel the fissures developing in their community. (Guess they got more than they bargained for with us.)