How might AIs think, feel, intend, empathize, socialize, moralize? Actually, almost any way we might imagine, and many ways we might not. To stimulate our imagination, we can contemplate the varieties of natural intelligence on parade in biological systems today, and speculate about the varieties enjoyed by the 99% of species that have sojourned the earth and breathed their last—informed by those lucky few that bequeathed fossils to the pantheon of evolutionary history. We are entitled to so jog our imaginations because, according to our best theories, intelligence is a functional property of complex systems and evolution is inter alia a search algorithm which finds such functions. Thus the natural intelligences discovered so far by natural selection place a lower bound on the variety of intelligences that are possible. The theory of evolutionary games suggests that there is no upper bound: With as few as four competing strategies, chaotic dynamics and strange attractors are possible.
When we survey the natural intelligences served up by evolution, we find a heterogeneity that makes a sapiens-centric view of intelligence as plausible as a geocentric view of the cosmos. The kind of intelligence we find congenial is but another infinitesimal point in a universe of alien intelligences, a universe which does not revolve around, and indeed largely ignores, our kind.
For instance, the female mantis Pseudomantis albofimbriata, when hungry, uses sexual deception to score a meal. She releases a pheromone that attracts males, and then dines on her eager dates.
The older chick of the blue-footed booby Sula nebouxii, when hungry, engages in facultative siblicide. It kills its younger sibling with pecks, or evicts it to die of the elements. The mother watches on without interfering.
These are varieties of natural intelligence, varieties that we find at once alien and disturbingly familiar. They break our canons of empathy, society and morality; and yet our checkered history includes cannibalism and fratricide.
Our survey turns up another critical feature of natural intelligence: each instance has its limits, those points where intelligence passes the baton to stupidity.
The greylag goose Anser anser tenderly cares for her eggs—unless a volleyball is nearby. She will abandon her offspring in vain pursuit of this supernormal egg.
The male jewel beetle Julodimorpha bakewelli flies about looking to mate with a female—unless it spies just the right beer bottle. It will abandon the female for the bottle, and attempt to mate with cold glass until death do it part.
Human intelligence also passes the baton. Einstein is quoted as saying, "Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe."
Some limits of human intelligence cause little embarrassment. For instance, the set of functions from the integers to the integers is uncountable, whereas the set of computable functions is countable. Therefore almost all functions are not computable. But try to think of one. Turns out it takes a genius, an Alan Turing, to come up with an example such as the halting problem. And it takes an exceptional mind, just short of genius, even to understand the example.
Other limits strike closer to home: diabetics that can't refuse dessert, alcoholics that can't refuse a drink, gamblers that can't refuse a bet. But it's not just addicts. Behavioral economists find that all of us make "predictably irrational" economic choices. Cognitive psychologists find that we all suffer from "functional fixedness," an inability to solve certain trivial problems, such as Duncker's candle box problem, because we can't think out of the box. The good news, however, is that the endless variety of our limits provides job security for psychotherapists.
But here is the key point. The limits of each intelligence are an engine of evolution. Mimicry, camouflage, deception, parasitism—all are effects of an evolutionary arms race between different forms of intelligence sporting different strengths and suffering different limits.
Only recently has the stage been set for AIs to enter this race. As our computing resources expand and become better connected, more niches will appear in which AIs can reproduce, compete and evolve. The chaotic nature of evolution makes it impossible to predict precisely what new forms of AI will emerge. We can confidently predict, however, that there will be surprises and mysteries, strengths where we have weaknesses, and weaknesses where we have strengths.
But should this be cause for alarm? I think not. The evolution of AIs presents risks and opportunities. But so does the biological evolution of natural intelligences. We have learned that the best way to cope with the variety of natural intelligences is not alarm, but prudence. Don't hug rattle snakes, don't taunt grizzly bears, wear mosquito repellant. To deal with the evolving strategies of viruses and bacteria, wash hands, avoid sneezes, get a flu shot. Occasionally, as with ebola, further measures are required. But once again prudence, not alarm, is effective. The evolution of natural intelligences can be a source of awe and inspiration, if we embrace it with prudence rather than spurn it with alarm.
All species go extinct. Homo sapiens will be no exception. We don't know how it will happen—virus, an alien invasion, nuclear war, a super volcano, a large meteor, a red-giant sun. Yes, it could be AIs, but I would bet long odds against it. I would bet, instead, that AIs will be a source of awe, insight, inspiration, and yes, profit, for years to come.