Definition

Although humans share 95% of their DNA with chimpanzees, and have brains only three times as large as chimpanzee brains, humans appear to be far better than chimpanzees at learning an enormous variety of cognitive domains. A bee is born with the ability to construct hives; a beaver is born with an instinct for building dams; a human looks at both and imagines a gigantic dam with a honeycomb structure of internal reinforcement. Arguendo, some set of factors, present in human brains but not in chimpanzee brains, seem to sum to a central cognitive capability that lets humans learn a huge variety of different domains without those domains being specifically preprogrammed as instincts.

This very-widely-applicable cognitive capacity is termed general intelligence (by most AI researchers explicitly talking about it; the term isn't universally accepted as yet).

We are not perfectly general - we have an easier time learning to walk than learning to do abstract calculus, even though the latter is much easier in an objective sense. But we're sufficiently general that we can figure out Special Relativity and engineer skyscrapers despite our not having those abilities built-in at compile time (i.e., at birth). An Artificial General Intelligence would have the same property; it could learn a tremendous variety of domains, including domains it had no inkling of when it was switched on.

More specific hypotheses about how general intelligence operates have been advanced at various points, but any corresponding attempts to define general intelligence that way, would be theory-laden. The pretheoretical phenomenon to be explained is the extraordinary variety of human achievements across many non-instinctual domains, compared to other animals.

Artificial General Intelligence is not par-human AI

Since we only know about one organism with this 'general' or 'significantly more generally applicable than chimpanzee cognition' intelligence, this capability is sometimes identified with humanity, and consequently with our overall level of cognitive ability.

We do not, however, know that "cognitive ability that works on a very wide variety of problems" and "overall humanish levels of performance" need to go together across much wider differences of mind design.

Humans evolved incrementally out of earlier hominids by blind processes of natural selection; evolution wasn't trying to desi...