Okay if I am remembering right. Whatever your Humanity is at, that is the max dice pool you can have for social interaction with humans. So like if your total dice pool for a situation is 8, but your Humanity is 5, then you get 8 when working with other vamps but only 5 for humans (as you are limited to your humanity score). Also if your score falls below 7, like 5 to 4, or 4 to 3, then you also have a chance of picking up a... I forget what they are called now, but a quirk or phobia or whatever.
That makes sense I guess, but then it made me wonder if they were trying to stranglehold you into playing a good guy by adding in lots of penalties for being evil. Just trying to decide if it was worth buying, as I would also want a hardcopy of nWoD (unlike the old Vampire, you need both the World of Darkness and Vampire books to play- as a note for those who don't have it). So it would be more like 60+ bucks for it, and I probably wouldn't play it too much, so I'm not sure yet...