There was a study floating around a couple of months ago that demonstrated that city mice develop larger brains than country mice. The study suggested, in a nutshell, that country mice, in an environment in which food is plentiful, don’t have to be very smart to get it; city mice have to grow bigger brains because they are more challenged to make their way in the world. Extrapolating, dependency makes populations stupid.
And thinking about our schools, I'd say it works the other way round, too.