Hey pal, there's a good whitepaper on that very thing from People Technologies the company behind the notorious PILAPT test battery. Here's the snippet you're after.
PILAPTŪ is a scientifically validated series of tests for assessing people’s aptitude for flying. Each test assesses a specific aptitude shown to predict performance in flight training. When tracking cadets through their first 134 hours of training, those scoring in the top 30% on the PILAPTŪ tests were shown to be more than twice as likely to succeed in training first-time when compared to the lowest 30% of scores. It is therefore possible to identify those with the highest success profiles.
SOURCE:
View Whitepaper
On receiving my own selection and PILAPT report on starting at CTC Aviation, my own score and those of my peers pretty much matched the above claim as we all sat in the "Top Band". Hope that helps. A write up of CTC Aviation's selection can be found
here.