Neolithic petroglyph is being touted as the world's oldest doodle:
These glyphs are found all over the planet. I wrote an article on them when
I found some in the California desert near Lone Pine (Owens Lake). My
thought was that if you give a small child a stick and sit them in sand (or
a crayon and paper), this is one of the first things they will draw. Basic
fractals are another.