Another hypothesis is that it is actually intelligence that causes social relationships to become more complex, because intelligent individuals are more difficult to learn to know.

We live in a time where there are all kinds of really, really smart people running around, saying that they've invented gadgets that will forever change our world.

So it's a type of that expanded to explain, I think, a lot of different things souls, spirits, ghosts, gods, demons, angels, aliens, intelligent designers, government conspiracists and all manner of invisible agents with power and intention, are believed to haunt our world and control our lives.