Wedrifid is not ignorant enough to think that most people are consciously hypocritical. Being consciously hypocritical is very difficult. It requires a lot of coordination, a good memory and decent to excellent acting skills. But as you may have heard, "Sincerity is the thing; once you can fake that you've got it made." Evolution baked this lesson into us. The beliefs we profess and the principles we act by overlap but they are not the same.

If you want to read up further on this go to social and cognitive psychology. The primary insights for me were that people are not unitary agents; they're collections of modules who occasionally work at cross purposes, signalling is realy freaking important, and that in line with far/near or construal theory holding a belief and acting on it are not the same thing.

I can't recommend a single book to get the whole of this, or even most of it across, but The Mating Mind and The Red Queen's Race are both good and relevant. I can't remember which one repeats Lewontin's Fallacy. Don't dump it purely based on one brainfart.