Why humans are so distinct from other species?

[Angrboda]

I'd first have to question the assumption that they do differ that significantly. There are some theories that the great increases in the size and topography of the human brain occurred as a result of their facilitating a range of social behaviors (language being the most obvious). I would suggest, along the lines of those theories, that we are not so much more intelligent than other species as individuals as we are, collectively, more effective as a group of social animals, than other species are. Things like the transmission of culture and knowledge through example and explicit teaching (originally from adult to child) allow the consolidation of advances in knowledge in a way that is not open to other species. (Other species, like chimpanzees, can learn by the example of others, but humans learn in a completely different way. Humans are the only species which makes a point of intentionally presenting examples to another [teaching] in order to create the conditions for learning. Other animals copy behaviors, but the behaviors that are open to them to copy are largely selected by accident and chance, rather than the intentional act of a caregiver. Another example is pointing [as with one's finger]. Humans understand this gesture, dogs understand it, but chimpanzees do not. Is this just an arbitrary species difference, or does it suggest that we [and dogs] are capable of understanding indirect reference in a way that other species are not?) Language is of course the supreme example of an intelligent and synergistic social technology. We don't have to lead another to the food a mile away, we can just tell them. We don't have to draw a bunch of triangles to illustrate a geometric idea, we can describe it in words. And we don't have to teach our children everything by example; they can learn words and propositions instead. And once language becomes writing, the ability to consolidate and transmit knowledge takes a quantum leap. The invention of writing is probably why the bulk of civilized existence is co-extensive with the existence of written language.

So, no, I rather doubt the initial premise that humans are in fact distinctly intelligent. Most humans contribute little in the way of intelligent achievement that isn't facilitated by culture and learning, and often the result of somebody else's thinking. As Newton said, if he has seen so far, it is because he has stood on the shoulders of giants. The rest of us are more like a pile of midgets, standing on each other's toes. Individuals contribute little; but our social behaviors allow us to accomplish a lot.

The group is intelligent as a whole; the species is more capable as a whole, because of these social behaviors; the individual human animal itself, though, is not that great a leap.

(There's an additional fact which I won't go into, but small improvements in global intelligence likely yield greater effects on overall functioning. The reason is because utilization of knowledge is a process having many steps, from efficiency in acquisition, to effectiveness in evaluating what to absorb and what to ignore, to efficiency and availability in recall, to greater effectiveness in synthesizing, reconciling and comparing information. Because a "global intelligence" makes each of these processes more effective, the overall result is more effective than whatever incrementally greater general intelligence the person has. So in effect, a person (or species) with slightly greater intelligence is able to make great gains because they are able to spend the same incremental difference at multiple points in the process. They get more bang for the buck because they're able to spend that same buck multiple times.)