Intelligence is a big deal. Humanity owes its dominant position on Earth not to any special strength of our muscles, nor any unusual sharpness of our teeth, but to the unique ingenuity of our brains. It is our brains that are responsible for the complex social organization and the accumulation of technical, economic and scientific advances that, for better and worse, undergird modern civilization.
All our technological inventions, philosophical ideas and scientific theories have gone through the birth canal of the human intellect. Arguably, human brain power is the chief limiting factor in the development of human civilization.
Unlike the speed of light or the mass of the electron, human brain power is not an eternally fixed constant. Brains can be enhanced. And, in principle, machines can be made to process information as efficiently as–or more efficiently than–biological nervous systems.
There are multiple paths to greater intelligence. By “intelligence,” I here refer to the panoply of cognitive capacities, including not just book smarts but also creativity, social intuition, wisdom and so on.
There are traditional means of enhancing intelligence, like education, and newer means like biotechnology. Perhaps the smartest and wisest thing the human species could do would be to work on making itself smarter and wiser. In the longer run, however, biological human brains might cease to be the predominant nexus of earthly intelligence.
Machines will have several advantages: most obviously, faster processing speed. An artificial neuron can operate a million times faster than its biological counterpart. Machine intelligences may also have superior computational architectures and learning algorithms. These “qualitative” advantages, while harder to predict, may be even more important than the advantages in processing power and memory capacity. Furthermore, artificial intellects can be easily copied, and each new copy can–unlike humans–start life fully fledged and endowed with all the knowledge accumulated by its predecessors. Given these considerations, it is possible that one day we may be able to create “superintelligence,” a general intelligence that vastly outperforms the best human brains in every significant cognitive domain.
The spectrum of approaches to creating artificial (general) intelligence ranges from completely unnatural techniques, such as those used in good old-fashioned AI, to architectures modeled more closely on the human brain. The extreme of biological imitation is whole-brain emulation, or “uploading.” This approach would involve creating a very detailed 3-D map of an actual brain–showing neurons, synaptic interconnections and other relevant detail–by scanning slices of it and generating an image using computer software. Using computational models of how the basic elements operate, the whole brain could then be emulated on a sufficiently capacious computer.
The ultimate success of biology-inspired approaches seems more certain, since they can progress by piecemeal reverse-engineering of the one physical system already known to be capable of general intelligence: the brain. However, some unnatural or hybrid approach might well get there sooner.
It is difficult to predict how long it will take to develop human-level artificial general intelligence. The prospect does not seem imminent. But whether it will take a couple of decades, many decades, or centuries, is probably not something that we are currently in a position to know. We should acknowledge this uncertainty by assigning some nontrivial degree of credence to each of these possibilities.
However long it takes to get from here to roughly human-level machine intelligence, the step from there to superintelligence is likely to be much quicker. In one type of scenario, the Singularity hypothesis, some sufficiently advanced and easily modifiable machine intelligence (a “seed AI”) applies its wits to create a smarter version of itself. This smarter version uses its greater intelligence to improve itself even further. The process is iterative, and each cycle is faster than its predecessor. The result is an intelligence explosion. Within some very short period of time–weeks, hours–radical superintelligence is attained.
Whether abrupt and singular or more gradual and multipolar, the transition from human-level to superintelligence would be of pivotal significance. Superintelligence would be the last invention biological man would ever need to make, since, by definition, it would be much better at inventing than we are. All sorts of theoretically possible technologies could be developed quickly by superintelligence–advanced molecular manufacturing, medical nanotechnology, human-enhancement technologies, uploading, weapons of all kinds, lifelike virtual realities, self-replicating space-colonizing robotic probes and more. It would also be effective at creating plans and strategies, working out philosophical problems, persuading and manipulating.
It is an open question whether the consequences would be for the better or the worse. The potential upside is clearly enormous, but the downside includes existential risk. Humanity’s future might one day depend on the initial conditions we create–in particular, on whether we successfully design the system (e.g., the seed AI’s goal architecture) in such a way as to make it “human-friendly,” in the best possible interpretation of that term.
Professor Nick Bostrom is director of the Future of Humanity Institute at Oxford University; his homepage with many of his papers is at www.nickbostrom.com.