Friendship isn’t always as serendipitous as it might feel; according to new research, there are just three ways people typically structure their social lives. When striking up new connections, people are either “tight-knitters,” “compartmentalizers,” or “samplers,” according to Dartmouth sociology professor Janice McCabe. Which one are you?

This Sunday on "Brain Games" (a show on Nat Geo), host Jason Silva will explore something he's calling "The God Brain", the possibility that believing in God may be "hardwired" in our brains.   Apart from being dinner party taboo, politically-charged, and intensely personal, this is a mysterious and complex subject. And, here's a guy who's taking a scientific approach to learning the potential connection between the physical and the spiritual.    Check out the Nat Geo write-up below and maybe tune your DVR to the show on Sunday.   "The God Brain — Is Religion Hardwired or Learned?"