Ah, well, I tend towards an embodied cognition point of view.

  I get there because humans are social creatures - so natural
  we're doing it even now, across the wires of the Internet.

  Our nervous systems extend towards and incorporate that which we
  bring "in" and extend out "to".

  I get there because babies not socialized through care *die*,
  even though fed/watered/changed. [famous sad case of 1930s
  German nursery if memory serves where the babies who were
  mechanically cared for died, but those who were nurtured lived].

  No socialization = death for humans.

  I mention socialization as it covers a lot of sensory inputs all
  at once. Look at how young children socialize with inanimate
  objects, babbling to a ball and such. Doesn't matter if the ball
  doesn't talk back. It doesn't have to for socialization to take
  place.