There shouldn't be a social field in npc_types anymore because it is no longer used. Even if you had the column in the db, it wouldn't work anyway because the code isn't functional.
I wasn't pointing the finger, KLS I asked a few devels and I agree it is a low priority bug anyway. As Angelox said, it will cause noobs to be better pullers
Though it is bugged. Most noob mobs shouldn't assist each other, and currently they all assist each other, whether they are the same race or not.