In regards to how women's weight affects their paycheck:Perhaps the characteristics that make a person successful (charisma, eloquent speech, confidence) are more thoroughly bred in people that are considered attractive since people are likely to choose mates with equal social value (i.e. successful fit or slender folks mating with other successful fit or slender folks ). These successful fit or slender folk go on to breed fit or slender babies for success. There have also been some studies to support that intelligence is actually correlated with attractiveness. Of course, intelligence factors into success. Personally, I feel that intelligence and other traits for success are not purely genetic. Then you have the thicker bodied people who are seen in our society as less attractive and perhaps receive less breeding for success, thus partially accounting for the lack of traits that contribute to "success" and higher paying jobs. Article "Beauty and the Brainy" -> http://www.washingtonpost.com/wp-dyn/articles/A64857-2004May28.html
I think there is also the cultural or environmental pressure or expectation to possess those traits. But I definitely agree that those who are perceived significantly "attractive" develop traits those traits - especially when we live in a world where we criticize Hilary Clinton for her "cankles" and fashion sense, despite her political background.
