As a sociologist, I've spent a lot of time studying people -- however, as the old anthropologist's joke goes: "sociology is anthropology done poorly, in our own backyard, covering just a hundred years of history." In truth, it's only recently that I've started to do some digging into the origins of this species I study all the time. This leads me to a question: how on earth did early hominids start using complex tools?
Let me preface this question with what I know already: 1) early hominids like homo habilis made stone tools, including (according to evidence) a simple axe made from a shaped stone attached to a wooden pole. 2) Chimps, along with some monkeys and other apes, use tools. These include stones for cracking open nuts, and sticks for scooping up ants and termites.
I admit, when I first saw chimps using tools in nature footage, I was floored. From this footage I learned that there are predilecitons among certian very clever, inquisitive mammals to extend their bodies with simple, one-piece tools. At first blush this impressed upon me how similar other apes are to ourselves. HOWEVER, now that I've gotten over the surprise, this kind of footage only seems to make human's use of complex tools more astounding. To make an axe you have to combine three things: stone, wood, and something to bind them. This is a whole order of magnitude different from the already astounding use of a single-piece tool (like a stick).
So here's my question again: What pushed homo habilis, who had a brain only 33% bigger than a modern chimp, to do something that no other animal has evidently ever done? Fundamentally, space ships, skyscrapers, and lasers are amazing, but they are just refinements and adaptations of the facility to make complex tools.
How the heck did homo habilis get started down this path, what pushed him, and why hasn't any other animal ever been pushed to do the same thing?