Intelligent being (species)

The classification by terrestrial humans of which species are considered intelligent beings has evolved over time. Humans have consistently been regarded as intelligent beings, while some non-human animal species have also been proposed for this classification.

There may be gradations in intelligence among different species. This topic is potentially sensitive and can involve accusations of speciesism. There are also possible differences in the distribution and variability of intelligence within species.

Note: For intelligence of individual beings, see intelligence.

In animal psychology, 'intelligent' in its broadest sense means any organism that is capable of learning, or of coming up with new responses to unfamiliar circumstances, rather than relying entirely on hard-wired instincts. A wide range of terrestrial animals have been shown to possess at least some 'intelligence' in this sense, ranging from great apes to birds, fish and even some invertebrates, such as octopuses and bees.

In discussions of extraterrestrial life, the term is often used loosely to refer to organisms that are intelligent in the way that humans are and all other known terrestrial animals are not. A more specific term for this sometimes used in technical discussions (and in science fiction) is 'sapient'.

It is also sometimes used to mean a conscious or sentient being. Some people take this to include humans but not other terrestrial animals. However, others would say that some or all terrestrial animal species do have this type of 'intelligence'. Views on this have varied widely over a long period of human history. Christianity, for instance, has generally taken the view that non-human animals have no souls. Hinduism, in contrast, takes the view that animals have the same kind of souls as humans and that in fact animals can be reincarnated as humans and humans as animals. The idea that no non-human animals were conscious used to be common among scientists, but in recent years the idea that many animals are sentient has been becoming popular in academia, due to mounting published evidence of this.

Other terms that overlap with 'intelligent being' or 'intelligence'

• Rational being. Literally, a being who is capable of reasoning. The philosopher John Locke, writing in 1690, discussing the meaning of the word 'man' and the distinction between the words 'man' and 'person', repeated an account he had read of a parrot that talked and answered questions as if it understood what it was saying, and commented that if this story was true, nobody would call the parrot a 'man' since the word 'man' includes the idea of 'a body, so and so shaped', but it would have to be considered a 'rational being'. Incidentally, whether or not this account was true, centuries later at least one researcher, Irene Pepperberg, is known to have taught several parrots to use words and answer questions with every appearance of understanding what they were saying.
• Sentient. Conscious of their experiences/able to experience feelings and sensations.
• Sapient.
• Is-be. A term for 'being' that comes from Alien Interview by Lawrence Spencer, also rendered as IS-BE, isbe, or ISBE. Linguistically, the term has been used interchangeably with "soul" or "spirit".