This discussion may contain spoilers!
One recurring theme I've picked up in Telltale's WD is human egotism in the midst of the zombie apocalypse, and how "love" (or at the very least, the drive to protect those closest to us at all costs) inadvertently brings out the worst in people.
Kenny doesn't give a rat's ass about the fate of others unless they directly affect his family; Lily doesn't care about anything beyond her father and his medication; Christa is so caught up with keeping Omid from death's clutches, she's oblivious to her own callousness; Molly is too busy being enraged at the people of Crawford to realize her "look out for number one" philosophy is dangerously similar to Crawford's; the Stranger hunts down and torments Lee on account of what he feels was done to his family; the St. Johns preserve themselves at the cost of their basic humanity; and Vernon betrays Lee's group strictly because he put the needs of his own group first.
There are precious few characters in the game who could be called genuinely selfless. Whether Lee becomes just another contributor to the state of the world around him, or tries to "go against the grain", is entirely up to the player. I hope this concept of self vs. selfless is carried over to S2.