Actually, from reading the article, it sounds like you can get an approximation by taking tests designed to measure your working memory and associative memory.
Yes, it's not so much a "languistic aptitude test" as it is a test of general intelligence. The isn't about separating the math geniuses (or whatever) from the language geniuses, it's about separating the lower intelligence enlisted men from the higher intelligence enlisted men.
It'd be a waste of everyone's time if all their results were just a bad IQ test. I checked the first paper, and as expected from competent researchers, they did check for general intelligence, using RAPM scores: http://blogs.bournemouth.ac.uk/research/files/2013/06/Psycho...
Those tests don't cover most of the test discussed here, though, since there's no assessment of phonemic processing abilities, resilience to distractions, etc.
