Why are there no nonhuman primates with an existing complex gestural language? One possible answer, it seems to me, is that humans have systematically exterminated those other primates who displayed signs of intelligence.
I would expect a significant development and elaboration of language in only a few generations if all the chimps unable to communicate were to die or fail to reproduce. Basic English corresponds to about 1,000 words. Chimpanzees are already accomplished in vocabularies exceeding 10 percent of that number.
Human spoken language seems to beadventitious. The exploitation of organ systems with other functions for communication in humans is also indicative of the comparatively recent evolution of our linguistic abilities.
I don't believe vegans (or vegetarians) who still get their (packaged, preservative/chemical-ridden) food from industrial food systems have any righteous ground to stand on, nor do I think a deep look at the sentient life of plants or the true environmental impact of agriculture permits them any comfortable distance from cruelty. Everything in this world eats something else to survive, and that something else, whether running on blood or chlorophyll, would always rather continue to live rather than become sustenance for another. No animal wants to be penned up and milked, or caged and harvested, and you've never seen plants growing in regimented lines of their own accord.
Having escaped the Dark Ages in which animals were mere stimulus-response machines, we are free to contemplate their mental lives. It is a great leap forward, the one that Griffin fought for. But now that animal cognition is an increasingly popular topic, we are still facing the mindset that animal cognition can be only a poor substitute of what we humans have. It can’t be truly deep and amazing. Toward the end of a long career, many a scholar cannot resist shining a light on human talents by listing all the things we are capable of and animals not. From the human perspective, these conjectures may make a satisfactory read, but for anyone interested, as I am, in the full spectrum of cognitions on our planet, they come across as a colossal waste of time. What a bizarre animal we are that the only question we can ask in relation to our place in nature is “Mirror, mirror on the wall, who is the smartest of them all?
In addition to Ameslan, chimpanzees and other nonhuman primates are being taught a variety of other gestural languages. And it is just this transition from tongue to hand that has permitted humans to regain the ability-lost, according to Josephus, since Eden-to communicate with the animals.
By standard intelligence texts, the dogs have failed at the puzzle. I believe, by contrast that they have succeeded magnificently. They have applied a novel tool to the task. We are that tool. Dogs have learned this--and they see us as fine general-purpose tools, too: useful for protection, acquiring food, providing companionship. We solve the puzzles of closed doors and empty water dishes. In the folk psychology of dogs, we humans are brilliant enough to extract hopelessly tangled leashes from around trees; we can conjure up an endless bounty of foodstuffs and things to chew. How savvy we are in dogs' eyes! It's a clever strategy to turn to us after all. The question of the cognitive abilities of dogs is thereby transformed; dogs are terrific at using humans to solve problems, but not as good at solving problems when we're not around.