There was also a recent report that ancient cave paintings might
have been made by younger (read teenage) people than once
thought:

http://www.livescience.com/history/060214_cave_art.html

HOW ART MADE THE WORLD

"The Day Pictures Were Born" (part 2 of 5)

Monday, July 3, 2006 10 - 11:00 pm

The second episode explores when and why humans underwent
what archeologists call the "creative explosion" and began making
pictures. The examination of prehistoric European cave
paintings and the rock art discovered in South Africa and North
America indicates that this "explosion" may have been an effort
to depict sights from the inner -- rather than outer -- worlds
of our ancient ancestors. (CC, Stereo)

Discover what your mind's eye sees in the dark in our online
interactive.

http://www.pbs.org/howartmadetheworld