shipway,
Psychometric testing features in many job selection procedures, the military, the Police force, I even heard in the news over the weekend that it is to be introduced as part of the driving test, and those who demonstrate a 'poor driving personality' will require more tuition before going through to the test itself.
I went through the NATS selection process in 1997. In recent years I have worked with our HR Recruitment team on a regular basis, with weekly contact with at least one of the team.
While up until a few years ago the psychometric 'testing' that was undertaken was not a pass/fail hurdle, it is now. The current tests are similar to those I sat ten years ago. Now, this is my own opinion, but it is not beyond the bounds of possibility that someone has sat down and collated all the data from the eight or more years of 'non-assessed' psychometric data, and cross referenced those results against the subsequent performance of each trainee ATCO. If trends were identified, for example if 'failures' tended to give a certain answer to certain questions, and successes tended to likewise give a certain answer to other certain questions, why shouldn't that data be used to determine selection?