You can read more about it here (it's where I found the best, ahem, definition)
However, I am not so sure these elements are really "African" elements, not to mention 5 elements ...
I am a little skeptical on this subject because I din't find any similar categorization of african art in the Italian, French and German litterature. Perhaps somebody could explain me better?
But, in the end, is there anything like the "5 elements of European art"? Or "the 5 elements of Asian art"?
Africa is as varied as their people. When you go to Sudan (I worked there), the Dinka are very high and tall and black while in the North you have people with thin noses (like in Ethiopia and Somalia) clear skin, sometimes clear eye colors.... Yet they are all Sudanese.
Arts and crafts varies greatly too ...like in music for instance...Is there any European, or American music today?
African art is beautiful, simple, fluid and delicate as well as bold and "abstract". It might be not perfectly realistic and figurative, but it's certainly more expressive than a perfect reproduction of a photo with ink and pen. At least in my opinion.
And I think that much influence on African art (like on any real art) have the material living conditons.
The Buddha statues in Asia are by the way also beautiful, simple, as if they were suspended in time similar to the picture of the African head in this page...