In Slovenia at least we have scholarships handed out to people who preform very well on aptitude tests, is this something that doesn't happen as reliably in the US?

Several states have merit-based scholarships (though these usually require performance in classes as well as aptitude tests, so there is a conscientiousness element as well as an intelligence element). I myself am going to university on a Bright Future scholarship. However, my impression is that federal need-based aid is a lot more common than state merit-based aid.