Greed vs Self-Preservation

One of the things I noticed keeps popping up throughout the novel is that there's a fine line between characters motivated by greed and by self-preservation. For example, is Hock Seng embezzling Anderson's bribe money because he needs it or because he wants it or because he thinks he needs it? Obviously everyone in the novel is looking for a better life and they're all willing to use different means to attain that life, but when the characters start doing things that we see as immoral, can they be justified by saying that they just live in a shitty world and they're doing what they can to survive? Why are there so few people who seem to be acting in the best interest of society as a whole? Even today people are outspoken about human rights and environmental problems, but the people in The Wind-up Girl just seem so complacent and only seem to worry about themselves and their families. At best, they only tolerate other people and are willing to screw them over in a heartbeat if it betters their own situation. This is of course influenced by their political climate, economics, and history, but everyone in the story still just seems so selfish. Did anyone else feel this way while reading? I found it hard to like anyone because most of the characters seemed so selfish.