To use prehistoric art as evidence of to any idea is dangerous, as we do not know anything about it for sure. But, thinking about those barbaric men into their dark caves making those oh-so-cool paintings, it occurred to me — the caves where hidden, it was difficult to get there, you had to crawl and grope in the dark and squeeze yourself through narrow holes…
This fact is very well known and many of the explanations for prehistoric art try to deal with it. I do not want to propose a new explanation, i just want to note that — together with all the ritual meanings and psychological links and aesthetic qualities and whatever — the dark and difficult to reach cave has secrecy.
If you draw a bison in the cave it will never know you did. If you draw your enemies, they will never know. And this makes a huge difference.
Animals do use communication. I suppose those first humans did, too. Sharing with others things that you saw or thought has lot’s of uses, and those pack-hunting primitive humans should have lot’s of ways to convey tactics and synchronizations during a hunt, and probably even other concepts, some of which not-useful. Nothing of that would make humans very different from other social animals, but somehow there is a difference.
The capacity to transmit behavior through extra-genetic means is violently effective, and that is what every communicating animal is exploring. But doing the same with secrecy can be even more so.
This doesn’t even need further discussion: when you learn a new trick you are the guy only until someone else can do the same. Even more importantly, a secret can give you an upper hand against foes or prey only until the foes discover what you are doing.
So for example, if you shout and point towards a direction, your pack mates can understand you are telling them to run that way, but so can the bison you are all hunting. But if you have a special way of shouting…
This could definitely spare our ancestors some nights of hunger, but i believe it could also lead in the long run to independent (and “natural-intelligence” free) development of language. The incomprehensible nature of language (rather than it’s communicative strength) could be the reason to develop a language in the first place!