a test of 'aptitude' = an 'aptitude test' [=a test that is designed to show how easily someone will be able to learn certain skills]
Anyone who can speak five languages obviously has a great natural 'aptitude' for (learning) languages.
The new test is supposed to measure the 'aptitudes' of the students.
(..) and in my opinion something Starfleet's lost. Why are you talking to me man? Because I looked up your file while you were drooling on the floor. Your aptitude tests are off the charts, so what is it? You like being the only genius level repeat-offender in the mid-west? Maybe I love it. (..)2009 Star Trek