Right ive just done an experiment with one of my youth strikers and Chris Iwelumo.
I signed Iwelumo because he had a determination of 20 + he also has several PPM's.
Tim Kelly is just a decent young player nothing special. I would have released him if not for this experiment.
After about 1 month a message came up saying that Kelly learns little for Iwelumo sighting there different personalities as the main cause.
I reloaded my save and the message did not appear. They continue to be linked.
I used FMM2.12 to sneak a peak under the hood to see what was going on.
Iwelumo Kelly(Before) Kelly(After)
Diff(Before) Change
Adaptibility 10 12 11 -2 -1
Ambition 16 14 15 +2 +1
Loyalty 12 18 18 -6 NC
Pressure 6 7 6 -1 -1
Professional 11 7 8 +4 +1
Sportsmanship 10 17 17 -7 NC
Temperament 15 13 14 +2 +1
Controversy 6 2 3 +4 +1
Determination 20 10 10 +10 NC
Also Kelly had gained Iwelumo's Play with back to goal PPM. This was all in the first month.
Notice that all stats that changed are closer to the mentors stats. Those that were two far way did not change.
This has shown that the stats change overtime and not just when tutoring finishes.