In the UK, as far as I'm aware, only CHC use psychometric testing. Bristow and Bond use other methods.
For CHC, there were (if I remember correctly) about 8 tests each aimed at different things e.g. coordination, spacial awareness, reasoning, learning ability etc. In addition there was an interview with a psychologist and a further test during that part too. (After all that was the Simulator Test btw)
Companies using psychometric testing have a particular set of results they are looking for - if you don't meet the criteria, that doesn't necessarily mean you are not a good pilot, just that you don't fit what the company is looking for. Another company might well be looking for someone just like you...
I've heard various statistics and rumours about these tests - they are (in no particular order!)
1) I've heard numbers along the line of "out of 17 applicants only 3 passed the tests". At the test I attended the pass rate was much better (80% pass rate)....
2) That they have a failure rate (and thus a rejection rate) of greater than 50% with these tests.
3) Experienced people (e.g. ex military pilots with '000s of hours) fail and are thus not hired. That is to say, the tests are a gate which have to be cleared - experience doesn't circumvent the process (in the majority of cases).
4) The tests are believed to be accurate. Those who pass the tests are generally able to complete the training and fly the line, those who fail (but are hired anyway), more often than not are found to be lacking at some subsequent stage...
As a final note, before I did the tests I didn't know a great deal about them. I found some books on psychometric testing and used them to try and "warm up". In the end though, I don't think it was worth it, since I never found any tests in the books that were similar to the ones I actually did.
So, if you get to do them, good luck! and if you are one of the people who don't fit the criteria, I wouldn't panic about it (easy for me to say I know) since there are many other companies (Onshore as well as off) who don't use those kind of tests and are looking for different skill sets.
BG.