I have always thought it odd that they painted the animals in almost picture-perfect detail, yet the did not paint humans at all. Whenever a human is depicted, it is usually a stick-figure or figures surrounding the animals.
I have a theory:
The paintings were not done by men, but by women.
The paintings of the animals are a ‘shopping list’.
The stick figures are equivalent to a football coach’s X’s and O’s diagrams for different plays for the field. IOW, “This is how YOU will kill the buffalo.”
Cave woman:
“Now, go out and bring back a buffalo for dinner!”..............
LOL! Good theory. :)