Does Your iPhone Have Free Will?

A new ‘Turing Test’ for free will can determine whether somebody, or something, thinks it has free will. And your iPhone may well pass

If you’ve ever found your iPhone taking control of your life, there may be a good reason. It may think it has free will.

That may not be quite as far-fetched as it sounds. Today, one leading scientist outlines a ‘Turing Test’ for free will and says that while simple devices such as thermostats cannot pass, more complex ones like iPhones might.

The problem of free will is one of the great unsolved puzzles in science, not to mention philosophy, theology, jurisprudence and so on. The basic question is whether we are able to make decisions for ourselves or whether the outcomes are predetermined and the notion of choice is merely an illusion.

This is not a question that is likely to be answered quickly or easily. But an interesting approach is to ask whether our latest insights and theories of the universe can throw light on the problem.

There are two relatively new ideas that are particularly relevant. The first is quantum mechanics, the theory that describes the universe on the smallest scale. The second is the theory of computation which underpins much of modern technology and most of what passes for research in artificial intelligence. What bearing do these theories have on our understanding of free will?

Today, we get an answer thanks to the work of Seth Lloyd, one of the world’s leading quantum mechanics and theorists, who is based at the Massachusetts Institute of Technology in Cambridge. Lloyd argues that quantum mechanics does not provide any mechanism that helps us understand free will. By contrast, he shows that the theory of computation is far more useful.

He argues that there are clear mechanisms in computation that make the outcome of a given calculation unpredictable, especially to the person or object making it. The key contribution of this latest work is a mathematical proof of this idea.

It is this inability to know the outcome of our own deliberations that gives rise to our impression that we possess free will, he says. And this limitation can form the basis of a “Turing test” of free will.

For many thinkers, the fundamental issue of free will is whether the deterministic laws of the universe can produce an intrinsically unpredictable outcome. If our thought processes are governed by these deterministic laws, then surely a given outcome is determined long before we begin to think about it.

For others, such as the physicist Roger Penrose, the issue is resolved by quantum mechanics, which is inherently probabilistic. If our thought processes are somehow governed by quantum mechanics, then it is no surprise that the outcomes can be unpredictable.

Lloyd comes down firmly on the side of the former. He says the probabilistic nature of quantum mechanics cannot resolve this problem. The philosopher Karl Popper once said that one of the key features of a decision arrived at by the process of free will is that it is NOT random, a point the Lloyd heartily propounds. “If determinism robs us of agency, then so does randomness,” he says.

Instead, his new work is on the role that the theory of computation plays in understanding free will. He uses this theory to prove that deciders— people or machines that make decisions— cannot in general predict the results of their decision-making process in advance. In other words, the outcome of a decision is unpredictable by its very nature.

The proof is an extension of Turing’s halting problem in computer science. This states that there is no general way of knowing how an algorithm will finish, other than to run it. What’s more, any attempt to determine the decider’s decision independently must take longer than the decider itself.

This means that when a human has to make a decision, there is no way of knowing in advance how it will end up. “The familiar experience of a decider — that she does not know the final decision until she has thought it all through — is a necessary feature of the decision-making process,” he says. That’s why we experience decisions as choices that are unknowable in advance—because they are!

Of course, this assumes that thought processes in humans are governed by the laws of physics and that these processes themselves can be simulated by general-purpose computer. For many thinkers, these assumptions will be entirely reasonable.

Lloyd ends by showing how this way of thinking leads to a simple set of questions that form a kind of Turing test for free will. The questions are these:

Q1: Am I a decider?

Q2: Do I make my decisions using recursive reasoning (ie using a process that can be simulated on a digital computer)?

Q3: Can I model and simulate — at least partially — my own behaviour and that of other deciders?

Q4: Can I predict my own decisions beforehand?

Provided you—or your iPhone—answer honestly, the answers give a straightforward indication about free will.

“If you answered Yes to questions 1 to 3, and you answer Yes to question 4, then you are lying. If you answer Yes to questions 1,2,3, and No to question 4, then you are likely to believe that you have free will,” says Lloyd.

So a simple device like a thermostat cannot believe it has free will, whereas a human can.

But what of devices with intermediate complexity, such as iPhones? “As computers and operating systems become more powerful, they become unpredictable — even imperious –in ways that are all too human,” says Lloyd. An iPhone “seems to possess all the criteria required for free will, and behaves as if it has it.”

So there you have it. Just make sure you know how to operate the off switch.

Ref: arxiv.org/abs/1310.3225 : A Turing Test For Free Will