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I've always wondered why humans are the only species on earth to build huge complex societies. Why aren't there multiple species of intelligent life on earth?

I've always wondered why humans are the only species on earth to build huge complex societies. Why aren't there multiple species of intelligent life on earth? (yes some animals are pretty smart, but they don't build cars, make movies, have laws, etc.)

grepherder 15y ago
Neanderthals? Yes with them our cousins there is the possibility of interbreeding having occurred, but most likely is that as a species as a whole they went extinct from competition. If even with our similarities and closeness there was enough competition to drive them extinct, I can hardly imagine any (land) species could have been thriving in coexistence with us.
baddox 15y ago
Perhaps multiple highly-intelligent species would be very unstable and likely to annihilate each other (at least if they both lived on land). Think about it: there's only one "superpower" right now.
- eru 15y ago
  China?
  - baddox 15y ago
    Not a superpower. Not yet.
Cushman 15y ago
Humans didn't do any of those things for several hundred thousand years, either.
toast76 15y ago
It pretty much comes down to having thumbs.
gwern 15y ago
Intelligence is expensive[1], and there may be some sort of threshold effect. Let's ignore the last few centuries of Revolutions, and look at the longer scale. Humanity is recognizable back to 200k years or so; civilization in any sense goes back maybe 5k years. How successful was humanity's intelligence during those 195k years? Not very: humanity spread slowly, did not represent a huge population, and suffered many reverses. And that's not even getting into arguments about what the (extinct) Neanderthals mean with their larger brains. [1] Metabolically and in other respects; if you doubt this, I've listed what I know about this in http://www.gwern.net/Drug%20heuristics http://www.gwern.net/Drug%20heuristics and especially the footnotes & hyperlinks.
- Cushman 15y ago
  > and suffered many reverses. I think this is a crucial point. If all of humanity had been wiped out in a famine in Africa fifty thousand years ago, there wouldn't be anyone sitting around today wondering, "Why is it there aren't any civilizations?" And there were probably millenia that went by when the odds of that happening dwarfed the possibility that we might survive long enough to develop a writing system.
blhack 15y ago
Because we're the only ones with language. Language gave us a huge technical advantage over all of the other animals. Typically, in species without language, it takes many generations for a "mutation"[1] to propagate across the species. If I instinctually figure out a better way of hunting deer, which gives me an advantage over my competitors for mates, and I pass it on to my children, who pass it on to theirs, etc. eventually the new instinct will be present in most of the species. (This is basic basic natural selection). Language changed all of that. Now instead of waiting for offspring to carry a mutation, I can just tell people about the better way of hunting deer, they can do it, and they can tell people too. Stuff spreads quickly. It makes humans able to evolve at a much, much, much faster rate than any other animal on the planet. (And yes, really, humans are the only animals on the planet with language. Bird song, whale song, and tree-pheromones don't count.) [1] In quotes because consciously iterating over a problem (like hunting deer) isn't a "mutation" in the classic sense.
- lifeformed 15y ago
  I guess the question is then: why are we the only ones with language?
  - nextparadigms 15y ago
    Probably because we could breed much faster than the others, and the others either went extinct on their own by being too isolated from us (and no interspecies breeding) or because we killed the last survivors, or both.
- joejohnson 15y ago
  There were other species with language (Neanderthals, other proto-humans). Some of these species coexisted, and there is some evidence that they fought one another, and maybe killed each other off.
  - blhack 15y ago
    >There were other species with language According to who? Neanderthals had the capacity for language, that doesn't mean they used it.
pm90 15y ago
If I have to hazard a guess, I would say : learning It is only humans that learn from their experience and pass it on. One generation teaches the next one what it learnt. If you sit still for a while and wonder just how we can make such complex things, its because we are building on the knowledge of those that came before us (I think Newton once said "If I have seen farther than others, it is because I have stood on the shoulder of Giants", which was a reference to Galileo, Kepler etc. all of whose work was important for Newton's own discoveries)

grepherder 15y ago

Neanderthals? Yes with them our cousins there is the possibility of interbreeding having occurred, but most likely is that as a species as a whole they went extinct from competition. If even with our similarities and closeness there was enough competition to drive them extinct, I can hardly imagine any (land) species could have been thriving in coexistence with us.

baddox 15y ago

Perhaps multiple highly-intelligent species would be very unstable and likely to annihilate each other (at least if they both lived on land). Think about it: there's only one "superpower" right now.

eru 15y ago
China?
- baddox 15y ago
  Not a superpower. Not yet.

Cushman 15y ago

Humans didn't do any of those things for several hundred thousand years, either.

toast76 15y ago

It pretty much comes down to having thumbs.

gwern 15y ago

Intelligence is expensive[1], and there may be some sort of threshold effect. Let's ignore the last few centuries of Revolutions, and look at the longer scale. Humanity is recognizable back to 200k years or so; civilization in any sense goes back maybe 5k years. How successful was humanity's intelligence during those 195k years? Not very: humanity spread slowly, did not represent a huge population, and suffered many reverses. And that's not even getting into arguments about what the (extinct) Neanderthals mean with their larger brains. [1] Metabolically and in other respects; if you doubt this, I've listed what I know about this in http://www.gwern.net/Drug%20heuristics http://www.gwern.net/Drug%20heuristics and especially the footnotes & hyperlinks.

Cushman 15y ago
> and suffered many reverses. I think this is a crucial point. If all of humanity had been wiped out in a famine in Africa fifty thousand years ago, there wouldn't be anyone sitting around today wondering, "Why is it there aren't any civilizations?" And there were probably millenia that went by when the odds of that happening dwarfed the possibility that we might survive long enough to develop a writing system.

blhack 15y ago

Because we're the only ones with language. Language gave us a huge technical advantage over all of the other animals. Typically, in species without language, it takes many generations for a "mutation"[1] to propagate across the species. If I instinctually figure out a better way of hunting deer, which gives me an advantage over my competitors for mates, and I pass it on to my children, who pass it on to theirs, etc. eventually the new instinct will be present in most of the species. (This is basic basic natural selection). Language changed all of that. Now instead of waiting for offspring to carry a mutation, I can just tell people about the better way of hunting deer, they can do it, and they can tell people too. Stuff spreads quickly. It makes humans able to evolve at a much, much, much faster rate than any other animal on the planet. (And yes, really, humans are the only animals on the planet with language. Bird song, whale song, and tree-pheromones don't count.) [1] In quotes because consciously iterating over a problem (like hunting deer) isn't a "mutation" in the classic sense.

lifeformed 15y ago
I guess the question is then: why are we the only ones with language?
- nextparadigms 15y ago
  Probably because we could breed much faster than the others, and the others either went extinct on their own by being too isolated from us (and no interspecies breeding) or because we killed the last survivors, or both.
joejohnson 15y ago
There were other species with language (Neanderthals, other proto-humans). Some of these species coexisted, and there is some evidence that they fought one another, and maybe killed each other off.
- blhack 15y ago
  >There were other species with language According to who? Neanderthals had the capacity for language, that doesn't mean they used it.

pm90 15y ago

If I have to hazard a guess, I would say : learning It is only humans that learn from their experience and pass it on. One generation teaches the next one what it learnt. If you sit still for a while and wonder just how we can make such complex things, its because we are building on the knowledge of those that came before us (I think Newton once said "If I have seen farther than others, it is because I have stood on the shoulder of Giants", which was a reference to Galileo, Kepler etc. all of whose work was important for Newton's own discoveries)