Golf is often cast as the ultimate individual challenge (which indeed it is). But at its heart, I believe, golf is a social game. Clearly, the golf club is a social organization, but let's talk social interaction within the context of golf course design. Here are a few features off the top of my head - that express the inherent social nature of golf...
1. The "patio" 1st tee/18th green. See Merion, Riviera, TOC, Troon and others. You have the opportunity to chat with other members, players about to go off, folks eating lunch, etc. Plays into the golfer's nerves tightly knits the clubhouse/golf shop to the golf course.
2. The "early return" routing concept demonstrated by George Thomas, who tried to bring the third hole near the clubhouse so games could be joined in progress. Pine Valley returns at the fourth hole. Again, increases interaction between on-course players and those who have yet to start or who are milling about the clubhouse after finishing. Lots of opportunities for watching, razzing, exchanging current round information, etc.
3. Shared tee complexes. Perhaps the most rare of all the "social" elements of GCA. I grew up on a course that had two of them. Cherry Hills has a nice one at #7/#13, although it could be made better, IMO. The great island shared tee at Maidstone is another. I loved the opportunity to watch other players, share quick jokes or news or frustration. Interior designers create common areas in order to allow for "human friction," the happenstance interaction between people. Lots of great stories as a result.
4. Shared green/fairway/bunker complexes. See above, although to a lesser extent, since these features cause players to intersect during the play of a hole.
5. Figure 8 routings and crossovers. I LOVE crossovers, where halfway houses/comfort stations/etc. serve players on multiple holes.
6. Open view corridors. TOC Old Macdonald didn't require too much effort to open the view corridors, but the ability to see so many games being played is one of the joys of a round at those places. I can't imagine what NGLA was like with trees bordering many of the holes. It's great to share a moment - even from far away - with friends on the course.
The idea of "never seeing another group on the course," somehow transmogrified into a marketing plus. Not for this golfer!
How else to do architects create "human friction" while also adding interest and challenge to the round?