I can't really recall the sites where I read this from (I think they were Dissidia sites), but they considered Cecil to be an antisocial person.
I don't really see him as antisocial. I mean, he is the leader of the team and he talks to important people a lot like the King of Fabul, the Mysidian Elder, and other people in high positions. He also seems to have no problems when it comes to talking to others. He isn't really hesitant in his speech or he doesn't try to cut conversations short.
The only instances where I can think of Cecil acting remotely antisocial was how he was hesitant to say good-bye to Golbez, though that was more of a forgiveness issue than an antisocial issue.
So what do you guys think?