Defining intelligence is not easy. Is it an ability for abstract thought? Communication? Reasoning? Problem solving? It's a troubling concept for humans because we know we have it but we're not so sure what, exactly it is.
And traditionally, humans have considered their intelligence to be superior to that of the rest of earth's inhabitants. Animals, it has long been thought, have a degree of intelligence but certainly nothing that could compare to humanity's proclivity for innovation and emotional understanding.
Recently, however, a series of observations have challenged this idea. Indeed, we humans are finally realizing that several animals—from our cousins the apes down to fish and even some invertebrates—experience deep emotion, develop culture, and utilize tools for problem solving; all things that were once the cornerstones of the human intelligence pedestal.
Any discussion of animal intelligence must begin with apes. There has been extensive and well-documented research that has found evidence of some key elements of high intelligence in ape species including self awareness, emotional understanding, problem solvind and reasoning, culture, and language.
Ever since Flipper hit theaters and TV screens in the 1960s, dolphins have been regarded as one of the most intelligent species on the planet. It was not until recently, however, that the true extent of this intelligence was acknowledged. Dolphins have exhibited "self-recognition, an understanding of symbol-based language, and distinct personalities." In fact, some scientists have called "non-human person" status for dolphins.
Another animal that has, upon closer examination, shown signs of higher intelligence is the elephant. As herd animals, elephants are used to living in groups. Recent research, however, revealed that elephants a capable of working together to solve problems. Evidence of this sort of collaborative ingenuity was surprising.
It's relatively easy to accept that other mammals exhibit high-level intelligence—after all, they tend to have big brains just like humans. Crows, however, defy the pejorative title of "bird brain." In fact, these clever birds have been observed crafting and using specific and specialized tools to gather food.
Fish, too, it seems share the ability to use tools to solve specific problems. Researchers have captured photos and videos of at least two reef fish species using rocks to crack open stubborn clam shells.
Tool use, it turns out, is not even limited to animals that have a spine. Scientists recently observed an octopus using a coconut shell as a mobile shelter. By carrying it along, the octopus could stop anywhere and crawl in, finding protection from potential predators while on the go.
Though no animal has exhibited the desire or ability to cooperate and transform the planet to the extent humans have, it's clear that many species deserve more credit than they been given in the past.