The reason I don’t believe we will ever develop artificial general intelligence

The reason I got interested in artificial intelligence is because the idea of artificial general intelligence, or AGI, amazed me.

It seems that the ambition of creating artificial life has inhabited people’s minds for millennia. In Greek mythology, Hephaestus forged and gave life to the bronze giant Talos, a form of artificial life.

Nonetheless, I currently believe that this hope will never be fulfilled. My argument underpinning this belief is short and based on a very useful heuristic, or rule of thumb, that I will lay out here. You can use this heuristic in many other situations, as I believe it is widely applicable and genuinely powerful.

Here is my argument :

The human brain is a system that is way too complex for us to understand and reproduce.

Now you might want to write an angry comment saying that this is no argument at all and that many things appeared too complex to us before we finally understood them, but read on for a little while.

To back up my claim, I will use as an example a paper written in 1978 by mathematician Prof. Sir Micheal Berry. I will admit that the paper is very technical and that I do not have the mathematical background to fully grasp it at the moment, I will thus rely on author Nassim Taleb’s account of this paper in his book The Black Swan. Imagine you are dealing with a billiard table with one ball on it :

If you know a set of basic parameters concerning the ball at rest, you can compute the resistance of the table (quite elementary), and you can gauge the strength of the impact, then it is rather easy to predict what would happen at the first hit. The second impact becomes more complicated, but possible; and more precision is called for. The problem is that to correctly compute the ninth impact, you need to take account the gravitational pull of someone standing next to the table (modestly, Berry’s computations use a weight of less than 150 pounds). And to compute the fifty-sixth impact, every single elementary particle in the universe needs to be present in your assumptions! An electron at the edge of the universe, separated from us by 10 billion light-years, must figure in the calculations, since it exerts a meaningful effect on the outcome.

The Black Swan, Nassim Taleb

As you can see, in this relatively simple system that seems to be the ball and the table, after a few tens of impacts, the trajectory of the ball becomes completely unpredictable. This is a property of complex dynamical systems, when experiencing very slight differences in initial conditions, the systems will first behave similarly, before completely diverging and taking radically different trajectories. A typical example of this is the double pendulum.

Now to come back to our initial subject, the brain, one could argue it is infinitely more complex system that a billiard table and a ball. If we cannot predict the behavior of a ball on a table after a certain number of impacts, could we really predict the response of a system composed of 100 billion neurons that interact together trough 100 trillion synapses to, let’s say, a pain stimulus ? Infinitely small variations in the stimuli could lead to widely different responses.

Indeed, the brain, like most sufficiently complex systems, displays characteristics of opacity (the brain is like a black box, we don’t know what’s going on inside), emergence (the system cannot be understood by looking at its parts) and non-linearity (changes in conditions can lead to a disproportionate responses) which make it extremely difficult to study.

Although the rise of Big Data and the explosion of computing power has allowed to build increasingly massive brain simulations, these remain biologically inaccurate. Furthermore, even if we were able to mimic the “hardware” perfectly, it would remain nearly impossible to produce the appropriate “software” to reproduce general intelligence.

Although I am genuinely interested in science, and I believe we still have many amazing discoveries to make, I do believe that some problems are just too complex to be solved. Implanting general intelligence in machines is one of them. Although engineers are sometimes incredibly resourceful, they simply cannot compete against billions of years of natural selection.

2 Comments

  1. The basic flaw in this argument is that it is not necessary to reproduce the human brain in order to produce AGI, and indeed I don’t think AGIs will be very much like it (just as ordinary AIs are not like it): https://www.lesswrong.com/posts/tnWRXkcDi5Tw9rzXw/the-design-space-of-minds-in-general

    Also, even if we were to model an AGI after a human brain, this doesn’t imply we would need to be able to predict its outputs in order to build it (just as you don’t need to predict the output from the two pendulums in order to build them).

    I would further argue that engineers can compete against billions of years of natural selection quite easily. Witness the circuit for adding two integers, which nature has perhaps never produced even once in billions of years. This is because the evolutionary process is stupid, and has no goal: https://www.lesswrong.com/posts/jAToJHtg39AMTAuJo/evolutions-are-stupid-but-work-anyway

    Liked by 1 person

    1. Although it is true that we do not necessarily need to mimic the brain in order to produce AGI, we would most likely need a model of roughly the same order of complexity as the brain. That is impossible with current means and perhaps permanently. Although science has allowed us to mimic and understand nature, I think we’ve been reaping the low hanging fruit for the last 400 years, and even that has been incredibly hard. AGI is the apple at the top of the tree. Complexity compounds, some systems are infinitely harder to crack than others.

      Engineers can compete against evolution on relatively simple problems, yes. We can model some relatively complex systems with partial differential equations too,but even that has limits. We are yet to understand anatomy and genetics, let alone how intelligence emerges from the brain.

      My post is not a formal proof, a la Godel, that AGI can’t happen. If I were able to produce that I would be receiving a Fields medal not writing a blog lol. So yeah although I did not disprove AGI, I still think it’s very unlikely to happen anytime soon. The less wrong community overhypes AGI imo. We should worry about AI weapons and big data fueled surveillance rather than AGI, which are technologies that already exist and to a large extent ignored by the media.

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