When I was young, I used to judge a book by its content, not by the number of praises it had. I always looked at the synopsis, and I found books with snippets of positive reviews in the back rather annoying.
Well, times have changed, and so have my perspective on the world- and books. These days, I am more attracted to books with plenty of praises in the back, or that have received many awards. I still look at the sypnosis, but the praises make up a bigger part of my decision to whether or not I should borrow it.
Now, if you take this little thought, and compare it to the world of the social nation, I think it might make sense. When you're a kid- you know, that time when you're naive, ignorant and all that great stuff- you wouldn't judge a person by what the other kids think of that person. You judge them by the real stuff- their personality, their heart. In all matter, the inside. It's so much harder to fall under peer pressure at that age, because kids are such free spirits, and they're not afraid to speak their mind. You don't rely on other people's judgement to decide whether or not you like that other kid. You rely on yours.
But then, as you grow older, the whole social system in school changes. Suddenly, you can fall to the bottom of the social chain if one the populars doesn't like you. And nobody would dare contradict the populars because, come on, they're the populars. Someone will judge you on what they heard from other people say about you. You might even judge somebody purely on how other people have described him/her.
I guess, the message that I'm trying to get out is that you (and I) should not judge somebody purely on the mental image you have of him/her, which was drawn by what everybody else has told you about that person. I mean, just like my "book theory", you don't want to judge a book only by what other reviewers or authors have said about that book. Read the sypnosis and use your own judgement to see if it would be good or not. Get to actually know a person, and then decide whether or not you like him/her.
Don't let other people's judgement prevail yours, because at the end, your judgement defines who you are as a person.