Gender bias

In english class recently, we have been learning about gender biases: Women portrayed as objects, and men portrayed as buffoons was the main example. There was interesting evidence about racial biases as well, and I was curious to see why advertising uses these, How prevelant they are, and how this affects people more then just demeaning them. I had some predictions about economic impact, but was suprised by what else I found.
First, I saw that it can actually affect patients being treated for heart disease. Women are referred less frequently for bypasses, and the like. Thats a direct harm on their quality and length of life. For the other side, Mexico is running ads to show men what it is like to be a woman, and that there needs to be change. Its goal is to be funny, and highlights the unfairness towards women in Mexican society.
In 2006, only 2% of ESPN air time was women's games. I quote, "[female] volleyball players must wear bikinis while they compete so people will be interested in watching." This might sound funny at first, but then realize its true. Women are so demeaned in sports, and on prime time TV. Not only do they have to be athletic, they have to be pretty too.
Of course, there are some problems with boys - and the effects of shown. "Only boys were shown in anti-social behavior. " And there is some progress over the years - girls have become more active.
I couldn't really find the reason why they are used, but it is likely economic - more girls are likely to like products with guys in them according to the above article. I was curious though, as I thought that "attractive" women would get men to buy the product, maybe if the women are subserviant they'll like it more, but why women aren't in the ads I wouldn't know. For sports, people tune out for for women more, and Men's sports are considered "more athletic and challanging".