A very short story on (the absence of) free will

April 26, 2020 • 9:45 am

This story was published in Nature some years ago and called to my attention by reader David. The author is the well known science fiction writer Ted Chiang, and though the story is 15 years old, it’s not only still relevant but, like the best sci-fi, makes you think hard. The story was published two years after Libet’s experiments showing that one could, using brain scans, predict with some accuracy when a subject was going to press a button before the subject became conscious of having made that decision. Since then, a host of other studies have shown that you can predict things that don’t involve physical actions, like deciding whether to add or subtract two numbers, up to ten seconds before the subject records having made a decision.

All the experiments show that brain scans can predict—not perfectly, mind you—what a subject will do before she has become conscious of that decision. And they cast severe doubt on the notion of libertarian free will: that at a given moment we could have decided to take any number of alternative decisions. People hate these results, and try to impugn them, for they don’t like the idea that decisions are determined by the brain before we think we’ve made them. People like Dan Dennett argue that if we fully grasp determinism, society will fall apart because we’ll become apathetic and refuse to get out of bed. This, of course, is not true. I got out of bed this morning and am busy writing this.

But to someone who’s science minded, determinism is the only game in town. Setting aside pure indeterminism—which would obtain if quantum processes affected our decisions—our choices and behaviors are the results of the laws of physics, and at any one time (leaving aside quantum factors) we could have made only one decision. If you doubt that, then you’ve bought into either the numinous, the supernatural, and mind/body dualism. Religious people, of course, are the most ardent believers in libertarian free will, because, at least in the Abrahamic faiths, you have a free choice about embracing God, Jesus, or Allah, and if you don’t you’re doomed.

I’ve harped about the hegemony of naturalism and determinism before, and emphasized its importance in structuring society and the judicial system. I won’t do it again; you can read what I’ve written by entering “free will” in the site’s search box.

I’ve also dismissed compatibilism as a semantic game constructed to ensure that people don’t become nihilisitic or depressed if they realize that they don’t have free will in the classical you-could-have-done-otherwise sense. The story below incorporates both determinism, a device based on the Libet experiment, and the supposed consequences of realizing that your behaviors are in fact determined. It’s a really nice and very short (1.5 page) science “fiction” story. Click on the screenshot.

The premise: people are given a Libet-ian device that predicts with a red light when they’re going to press a button on the device. They can’t outwit it because it’s apparently been programmed with every bit of information in the Universe. The consequences: many people go nuts.

Some excerpts (but just read the story):

By now you’ve probably seen a Predictor; millions of them have been sold by the time you’re reading this. For those who haven’t seen one, it’s a small device, like a remote for opening your car door. Its only features are a button and a big green LED. The light flashes if you press the button. Specifically, the light flashes one second before you press the button.

Most people say that when they first try it, it feels like they’re playing a strange game, one where the goal is to press the button after seeing the flash, and it’s easy to play. But when you try to break the rules, you find that you can’t. If you try to press the button without having seen a flash, the flash immediately appears, and no matter how fast you move, you never push the button until a second has elapsed. If you wait for the flash, intending to keep from pressing the button afterwards, the flash never appears. No matter what you do, the light always precedes the button press. There’s no way to fool a Predictor.

The heart of each Predictor is a circuit with a negative time delay — it sends a signal back in time. The full implications of the technology will become apparent later, when negative delays of greater than a second are achieved, but that’s not what this warning is about. The immediate problem is that Predictors demonstrate that there’s no such thing as free will.

There have always been arguments showing that free will is an illusion, some based on hard physics, others based on pure logic. Most people agree these arguments are irrefutable, but no one ever really accepts the conclusion. The experience of having free will is too powerful for an argument to overrule. What it takes is a demonstration, and that’s what a Predictor provides.

Typically, a person plays with a Predictor compulsively for several days, showing it to friends, trying various schemes to outwit the device. The person may appear to lose interest in it, but no one can forget what it means — over the following weeks, the implications of an immutable future sink in. Some people, realizing that their choices don’t matter, refuse to make any choices at all. Like a legion of Bartleby the Scriveners, they no longer engage in spontaneous action. Eventually, a third of those who play with a Predictor must be hospitalized because they won’t feed themselves. The end state is akinetic mutism, a kind of waking coma. They’ll track motion with their eyes, and change position occasionally, but nothing more. The ability to move remains, but the motivation is gone.

The reason that people go nuts in this scenario, which doesn’t occur with determinists like me, is apparently that they get a repeated, irrefutable, and tangible demonsration that they can’t choose otherwise. I guess this demonstration hits closer to home than simply the mental realization that our choices are determined before we’re conscious of having made them. But why would people buy such a device if the chances are high it would drive them nuts? (They have no choice, of course!)

Setting aside the fact that it would be impossible to build a Predictor, for it has to be in possession of all the information in the Universe, including things that happened up to the last second, it would be a useful way of demonstrating determinism. There are other problems with the description as well, but I’ll let you suss them out.

The end of the story? The narrator sends a warning back to the past about the dangers of the device:

And yet I know that, because free will is an illusion, it’s all predetermined who will descend into akinetic mutism and who won’t. There’s nothing anyone can do about it — you can’t choose the effect the Predictor has on you. Some of you will succumb and some of you won’t, and my sending this warning won’t alter those proportions. So why did I do it?

Because I had no choice.

A nice story!


Live Long and Evolve

July 12, 2019 • 10:15 am

by Greg Mayer

Much of the time while Jerry was in Hawaii, I was traveling in New York and New England, including attending Evolution 2019 in Providence, RI, the annual joint meeting of the Society for the Study of Evolution, the American Society of Naturalists, and the Society of Systematic Biology. The opening night is highlighted by the Stephen Jay Gould Prize Public Outreach Lecture. The Prize is given for “sustained and exemplary efforts [that] have advanced public understanding of evolutionary science and its importance in biology, education, and everyday life”. This year’s Prize winner was Jerry’s erstwhile Ph.D. student Mohamed Noor of Duke University.

Mohamed Noor in his Starfleet uniform. (Which show is the uniform from?)

The title of his lecture was “Evolution in the Final Frontier: Why Might We See So Many Humanoid Aliens in Star Trek?” He delivered it to a packed house, some in Starfleet uniform. (The opening night is open to and advertised to the general public.) Mohamed is the author of Live Long and Evolve (Princeton University Press, 2018), and his talk dealt with one of the topics in the book.


Some of Star Trek‘s writers have been renowned science fiction authors, and the franchise has long been known to pay attention to the scientific commentary about the series. My favorite example of this is the “Heisenberg compensator“. When it was pointed out that Heisenberg’s uncertainty principle (which states that either the position or the velocity of a particle could be known, but not both) meant that transporters would have a hard time doing what they are supposed to do, Star Trek writers invented the “compensators”, which, in some unknown fashion, overcame this difficulty.

Mohamed’s talk dealt with another such issue: why do alien species from all over the galaxy look so much alike? And so much like us? You know—roughly bilaterally symmetric, 4-limbed, bipedal, encephalized, the head with eyes, ears, nostrils, a mouth. The aliens might be a different color, or have head ridges, even antennae, but they look very human. The short, and probably pragmatically correct, answer is that the aliens had to be played by human actors, and anything else would be either undoable, prohibitively expensive for a TV series, or both. But Star Trek wanted a principled answer.

Image result for star trek humanoid aliens
A diversity of humanoid Star Trek aliens. From extremetech.com.

The principled answer that I knew of came from The Next Generation series, in which a species-diverse group of current humanoids encounter a recording made by an “ancient humanoid“, which explains that they had “seeded” planets across the galaxy with DNA that would drive evolution on those planets in a humanoid direction. It was never explained how this would work.

Mohamed’s careful study of Star Trek encountered two other explanations, both in the original series: humans derive fairly recently from visiting alien astronauts; or, aliens (most of them anyway) are derived from life on Earth. Rather than give Mohamed’s choice from among these three which is most plausible given what we know about evolution and genetics, I’ll leave it as an exercise for readers to think about, or debate in the comments (or, you could read his book!).

I’m about halfway through the book now, and as a long time Star Trek fan, I am fascinated. I have not yet gotten to the chapter which discusses all those interplanetary hybrids (like Mr. Spock), and am looking forward to it. In the book, Mohamed usually introduces each topic with a Star Trek scene touching on an evolutionary or genetic topic, and uses that as a launching point to discuss the biological principles involved. Among the topics he covers are common ancestry, phylogenetic trees, natural selection, convergence, genetic drift, what DNA is, and how DNA ‘works’. And I’m not finished yet!

The book is aimed at the general public (i.e., it is not a textbook), and Mohamed gives the most generous reading possible to Star Trek‘s scientific forays—it is not a compilation of errors. Footnotes give references to further Star trek episodes, and references in the comprehensive endnotes cover the scientific literature very well, including in areas outside Mohamed’s own areas of research. Many of these references are to the latest literature; the suggested reading adds more accessible works, including Dawkins’ Blind Watchmaker, and, of course, his mentor’s Why Evolution Is True. In fact, near the beginning of his lecture, he gave a shout-out for WEIT (the book).

Mohamed has long used science fiction to teach science, and been much involved in outreach activities, as regular WEIT readers will recall. In 2017, the Evolution meetings and Heroes and Villains Fan Fest/Walker Stalker Con were both being held simultaneously in Oregon Convention Center, and Mohamed attended both! You can see videos of him engaging scientific topics through science fiction here, here, and here, and a Star Trek vs. Star Wars debate. There are also a number of videos of his students making presentations at his Youtube channel.

Vincent van Gogh sees his legacy

March 30, 2019 • 1:30 pm

After visiting the van Gogh Museum and then seeing all the van Gogh key rings, tee shirts, and coffee mugs on sale at the Flower Market, I said to my friend, “Wouldn’t van Gogh be amazed if he could be here today and see how beloved his work is?”

Alas, that will never be:  the man died thinking he was a failure. But Grania sent me a short clip from an episode of Doctor Who in which the Doctor and his companion bring Vincent to the Musee d’Orsay to show him what happened. It’s very moving.

Tomorrow: in which I eat a raw herring!