To draw for a moment from an entirely different corner of my life, that part of me still attached to the biological sciences, there is ample evidence that animals -- rats and monkeys, for example -- that are forced into a subordinate status within their social systems adapt their brain chemistry accordingly, becoming 'depressed' in humanlike ways. Their behavior is anxious and withdrawn; the level of serotonin (the neurotransmitter boosted by some antidepressants) declines in their brains. And -- what is especially relevant here -- they avoid fighting even in self-defense ... My guess is that the indignities imposed on so many low-wage workers -- the drug tests, the constant surveillance, being 'reamed out' by managers -- are part of what keeps wages low. If you're made to feel unworthy enough, you may come to think that what you're paid is what you are actually worth.