RE: Body Language.
Move slow, talk slow, be an approval giver (not a seeker). We all have the capacity to be at the level of Bill Clinton or other legendary communicators - we do it on first dates, job interviews - he does it all the time. One of my most networked/outgoing friends consciously goes into certain situations like 'she owns the venue'. Also if you talk to everyone, you can hide the fact that you are interested in not everyone. You might also try videotaping your body language when you are with friends/familiar situation vs strangers/safe situation. You will have to try this to realize the power of this - but if you really, really want to talk to a group or even a cute female who is seated alone/together, drag a chair over from the other side of the room (noisily if possible) and sit down with them. That demonstrates commitment and is an opener all-in-one.
RE: Peer ratings
They are a form of social proof (raters do not exist in a bubble).
"Similarly, a person who has been unemployed for a long time may have a hard time finding a new job - even if they are highly skilled and qualified. Potential employers attribute wrongly the person's lack of employment to the person rather than the situation. This causes the potential employers to search more intensively for flaws or other negative characteristics that are "congruent" with or explain the person's failure and to discount the applicant's virtues."
http://en.wikipedia.org/wiki/Social_proof
RE: SES
One of the more clever and disturbing ways to gain 'power' over an individual is to play the student in the master-student role. E.g. by having them teach you something - which is doing you a favor, you can gain their favor.
Ben Franklin: http://news.ycombinator.com/item?id=145544
Poor people who go to Berkeley are likely to be moving up in the world relative to their families; their eyes are being opened to a whole new world of knowledge and power and all that, and they are humbled by it.
Rich people who go to Berkeley are likely to come from prep schools, and feel vindicated by having been admitted to a top school, and therefore are snooty.
The conclusion doesn't jibe at all with my personal experience, either, and I think this is why.
Through college, I had a weak posture, submissive body language, and tended to fidget/move around. I often looked goofy.
About six months ago, I decided to improve all that. I consciously developed an upright, chest-out posture. I cut down or eliminated unnecessary motions. I keep my hands extended and parallel to the arms, instead of close-fisted and angled inwards. I keep my chin up and my gaze high. I keep my legs outward and, when comfortable, spread apart.
By now, it's all become second nature. And it works. Women react much more strongly to me (in a good way). I feel more confident. My body image has greatly improved.
As software developers, most of us spend a lot of time seated in chairs and have less than Adonis-like physiques. I highly recommend body language hacking.