and yes,
I think the reason Jack has 20 majors and Hunter has none is mindset.
i.e. putting majors and Ryder Cup in their proper perspective, preparing properly. without becoming obsessed, and then executing.
If it's simply that the Ryder Cup is soooo much more pressure than when Jack played, why does Hunter have no majors?
I'd argue that he simply doesn't perform at peak level at the times most important to him-but in the rank and file tour events his game resurfaces.
which is why Jack is trying to mind jedi the Americans into presenting the games they show up with at rank and file Tour events. (the Ryder Cup courses certainly are generally rank and file 
)
I'm pretty sure if the Ryder cup had been as big a deal in 1981 as it is now, Jack would've done ok.
There are 2 mutually exclusive points I'm trying to make:
1. There is more pressure on the Ryder Cup (i.e. the deciding match) than there is on a "normal" major. Major champions from both sides have said this (Faldo, McDowell, Irwin). There is also more pressure than there used to be when Nicklaus was playing.
2. The reason that Jack Nicklaus has 18 majors and Hunter Mahan has none is because he was a vastly superior player in all ways (i.e. physical, mental). Mahan has "only" won 6 regular tour events, Nicklaus won 55 so it is not just majors where the gulf is vast. Nicklaus would have done well in the current Ryder Cup because he was the best player that ever lived.
Personally, I don't care that much about the Ryder Cup. I'll watch it but it is not the be all and end all that some people over here make it out to be. I also think the US will win big this year. They have the better team and they are at home.