<p>I'll second the previous comment about the majority of students being upper-income. One study found that at the top 146 colleges, 74% of the students are from the top economic quartile, while only 3% are from the bottom one. It's a fact that the higher your income, the more likely you are to be qualified for college - SAT scores are highly correlated with income, as well as non-quantifiable factors. For example, students who come from the higher income brackets tend to have the money for tutors, SAT prep classes, music lessons, service trips to other countries, summer programs, college counselors, etc. Not to mention that they tend to be able to go to better schools (either private ones or public schools in strong districts) with lots of advanced classes, extracurricular activities of every kind, and so on. That's why legacy students at top colleges get in at much higher rates - not so much because of explicit preference (there's little of it), but because they're naturally the most qualified students out there, having come from well-educated parents with higher incomes.</p>
<p>I'm a low-income student and when I was starting out at Stanford, I was afraid that everyone would be rich and snooty. I couldn't have been more wrong. Of course, there are some who are entitled and snooty, but they're few and far in between. My first roommate was rich (son of an investment banker in oil industry); another good friend I made early on that year was also rich (daughter of a chairman at a tech company); and my closest friend from college is very well-off (son of a well-known scientist, a high-up at a pharmaceutical company). Then there was me, coming from a family who was living far below the poverty line. Despite our radically different backgrounds, it was never an issue. It never interfered with our friendship - it rarely even came up. I started out thinking that all the rich people at Stanford were going to make assumptions about me, but I eventually realized that I was making assumptions about them. </p>
<p>Takeaway point: don't assume that rich people are necessarily snooty. They can be, of course, but likewise poor people can be very presumptuous about rich people. Go in with an open mind and you won't have to worry about how wealthy your classmates are.</p>