Quote From: pardelopeResearch has shown that people who's bodies and faces are symetrical are perceived as being more attractive i.e. better potential breeding stock. This response is subliminal and "hard-wired" - even babies react more positively to "attractive" people (of either gender). There is obviously a benefit to the individual (and our species) for attraction to symetry - probably as it is believed to indicate better health and genes. 
 
Throughout history, fashion and culture has played a role in what is perceived as "beautiful" (I should have been born in some Pacific Island culture in the 18th century when fat was considered beautiful). 
 
Most people are not aware of how they are influenced by these factors. They don't care if a "plain" or "ugly" person has a miserable life (as long as it is not themselves). The "beautiful" get more sex-partners, more wives, more money, lesser punishments, more trust, more opportunities etc etc.  
 
Sorry to say, not being beautiful has quite often meant death in certain situations throughout history. Being beautiful sometimes allowed a person to survive. 
 
Despite all this, I am hopeful that humans will eventually evolve and become aware of their inate and acquired prejudices - probably many generations hence. 
Research such as this can be manipulated.
I,as well,have read the research about the babies and looks.Frankly it doesn't make sense.Babies and toddlers react positively to whatever they are used to.
Even your own posting states that the perceptions of beauty change all the time.How would a baby know whether the "European look" or "girl next door look" is in ?They don't.They just go by what they are used to.
Being viewed as beautiful often meant death throughout history too.How many beautiful women were thought to be witches?
You stated:"The "beautiful" get more sex-partners, more wives, more money, lesser punishments, more trust, more opportunities etc etc.
If that were true than porn stars and strippers would rule this world -and they don't!
Do you know who the most powerful woman in America was for 2005 - Condoleeza Rice! Not Paris Hilton, Jessica Simpson or a Playboy bunny.A few years ago it was Oprah Winfrey.
As for the top 10 most powerful men,well, let's just say there weren't any Brad Pitts no matter how many veneers and hair transplants they had.
Lesser punishments?If you ever get a chance to do some work at a men's prison or you know someone who works there just ask them how the men look.That is where all the good looking men are so your "more pretty lesser punishment" theory is not so.