IMHO the social interaction varies significantly depending on what board game you play. Some easier games will allow you to small-talk while more complex games need your undivided attention at times. This, of course, doesn't even mention how competitive a game is.
In my groups there are really two types of meetups:
1. We meet to socialize and then end up playing a game or three. Those are usually lighter games so we can get up, walk around, get caught up in a little conversation in the kitchen while grabbing a drink, etc. During these times the socializing is clearly our foremost concern. We wouldn't play StarCraft is such a setting. Mostly because my group is so diversified that there will always be at least one player who hasn't played StarCraft yet. Having to go through 1-2 hours of explaining a game when all you really want to do is socializing is just not practical.
2. We feel the urge to play a specific game and then we get the right players together to make it happen. In this case we clearly met for a specific reason so socializing is done but only inbetween players' turns. There may be a break to order food or pop something in the oven, but all in all we met to play a game. Most talking will usually revolve around the game...with some exceptions, of course.
I think there are games out there that are much more suitable for an evening of leisurely socializing than StarCraft. Using StarCraft in your research may not reflect the actual goings-on.
Also, at several game nights I go to people meet and mingle regardless of whether it's game night or not. Some will choose a game based on wanting to hang out with (a) specific player(s) for an hour or two, some will choose a specific game based on what they want to play and then go find players who share that interest/passion. However, I have never seen most of the more complex games by FFG being played to mingle with specific people.