For aptitude testing, ADF Recruiting uses a version of the WOMBAT system from Aero Innovations -
http://www.aero.ca/e_main.html - which provides a very accurate measure of the applicant's aptitude in certain tasks.
Milt, you mention "pondering how to determine levels of human dexterity and co-ordination of brain function with muscular control as related to pilot aspirants" - ponder no more, this test does it all. That and the other batteries of tests given pilot applicants on the "Spec Testing" day give recruiters a very solid picture of the overall suitability of the applicant to perform the job.
Years of using these tests have given them the confidence to apply certain cutoff points with the scores.
These days, I believe much less emphasis is placed on academic achievement, however the testing will quickly determine if the applicant lacks basic mathematics skills essential in the cockpit.
This testing does not necessarily mean the applicant wouldn't be suited to a civilian flying career. The Defence Force is looking for a higher level of capacity for training, for learning and applying new material quickly, etc. I am told by those who have been through the system how easy it is to be scrubbed by failing one flight test. Tough, yes, but they aren't interested in babysitting people who might get it right with lots of practise - they're interested in the ones who will get it right quickly.
And they have the luxury to be choosy. There are still thousands of initial applicants who dream of being pilots. No shortage there. The hard part is holding on to the good ones. This is why if you are in the Defence Force as an aviator for longer than 10 years, you get almost an extra $30,000 per year just because you CAN fly. This is how a Major can be earning over $100,000 pa before he gets out of bed. If a helicopter pilot leaves the Defence Force he'd be lucky to be on 80% of that if he found a job at all.
See the bottom of page 8 of this thread for a bit more of a description of the overall process.