Player Interaction

This is one of the many questions about the vague inner-workings of Football Manager that I expect many of us have had. To what extent do the players affect each other by their mere presence?

Obviously we all know that having preferred personnel or friends together in a team would have a positive result - maybe an increase in team morale or team cohesion.

So we could then assume that a negative interaction between players, be it a failed tutoring attempt, or personal differences, would have the reverse effect - a decrease in morale or cohesion.

But what about an instance where you're playing as Man City and you sign Caballero to compete with Joe Hart for the No.1 jersey - will the presence of another good goalkeeper affect Hart in any way? Will it make him up his game a bit, as it would in real life? The same goes for any postion on the pitch. (I imagine this would be implemented through personal attributes. Maybe when a new star player arrives, in the same postion as an established player in the team, they would both recieve an automatic increase to their ambition and pressure (assuming this affects match performance))

Does FM have a mechanism for this? Does it recognise the effect of player competition on performance? Or is the general positive-negative as far as player interaction goes?