"Or maybe the men courted the women by dragging and carrying big stones to make them pretty pictures in the earth. "
that goes hand in hand with my theory that men invented civilaztion to impress chicks. :)
Grog didn't care about impressing chicks, he just took what he wanted.
The little nerds in the tribe didn't care about impressing chicks either,
but formed alliances in an effort to force Grog to let them have
access to the chicks too.
These alliances created rules for the distribution of chicks among it's members.
Eventually these allied nerds coined the phrase "civilized" to describe their system of getting chicks.
In conclusion, civilization was invented to keep Grog from crushing their nerdy heads for messing with his chicks.