False. Human behavior is much more complex than that. Rather, consider how the student's done in high school: Has the student opted for challenging classes, worked hard in those classes, kept up with his reading, been conscientious about his work -- that is, without prompting from you? If so, he's likely to continue to do the same thing in college. Has he been appreciative of things you've provided for him in high school, or does he have an "entitlement attitude"? Again, he's likely to do the same thing in college. Is he serious about going to college and is he excited about his potential classes and career, or is he just going because "it's what people do after high school"? A student who's ready and mature is going to do well regardless of who's paying, whereas a student who isn't really ready won't do well regardless of who's footing the bill.The one thing I know for sure is that the more of their own money in the game, the higher the grades!
Case in point: We've covered everything for our oldest, and she's earned only two Bs in her first two years of college.