Human brains have to be deterministic (though indeterminism would not give us free will anyhow)

Are human brains deterministic? That is, are the decisions that our brain makes the product of the prior state of the system (where that includes the brain itself and the sensory input into the brain), or does quantum indeterminacy lead to some level of uncaused randomness in our behaviour? I’ll argue here that our brains must be largely deterministic, prompted by being told that this view is clearly wrong.

First, I’ll presume that quantum mechanics is indeed indeterministic (thus ignoring hidden-variable and Everettian versions). But the fact that the underlying physics is indeterministic does not mean that devices built out of quantum-mechanical stuff must also be indeterministic. One can obtain a deterministic device simply by averaging over a sufficient number of low-level particle events. Indeed, that’s exactly what we do when we design computer chips. We build them to be deterministic because we want them to do what we program them to do. In principle, quantum fluctuations in a computer chip could affect its output behaviour, but in practice a minimum of ~50 electrons are involved in each chip-junction “event”, which is sufficient to average over probabilistic behaviour such that the likelihood of a quantum fluctuation changing the output is too small to be an issue, and thus the chip is effectively deterministic. Again, we build them like that because we want to control their behaviour. The same holds for all human-built technology.

There may be some instances where genuine non-deterministic randomness might be useful. An example is running a Monte-Carlo simulation (a technique, widely used in science and engineering, of computing a simulation that allows for all possibilities). But, even here, in practice, one usually uses deterministic pseudo-random-number generators, simply because our computers — despite being built on quantum mechanics — don’t actually do genuine randomness.

Our brains are also built to do a job. They are the product of a genetic recipe, a recipe that is the product of evolution. In evolutionary terms the job of a brain is to make real-time decisions based on that genetic recipe and on the local circumstances, as informed through the senses. And brains are hugely expensive in evolutionary terms, consuming 20 percent of the body’s energy and (for example) forcing big compromises in female anatomy and making childbirth dangerous.

It follows that brains could not have evolved unless they were strongly selected for (they cannot just be byproduct “spandrels”), which means they must serve the interests of the genes that specify the recipe, and that means that brain behaviour (the choices they make) must be strongly influenced by the genes. And, since those choices can be being made decades after the childhood brain develops out of the genetic recipe, it follows that there must be a deterministic chain of causation that holds over generational timescales.

To head off misunderstandings, the above is not saying that behaviour is entirely specified by genes. (Whenever anyone argues for genetics being a major factor in anything, it is often attacked as being the claim that genetics is the only factor; the reality is that everything is always a product of both genes and environment.) Obviously, the brain’s job is to make decisions reflecting the local circumstances, but how to react to particular circumstances must be strongly influenced by genes, otherwise the brain could not have evolved. Nor is this saying that the environment and stochastic factors have no effect on how the genetic recipe plays out and as the brain develops; of course they do. And nor is this saying that the brain’s neural network is static and unchanging. Of course it isn’t (memories, for example, and changes in the network). But this argument does show that there must be a deterministic chain between genes and brain behaviour that holds over multi-decade timescales. It must be the case that, in general, “that behavioural decision could have been different if, three decades ago, that gene had been different”. That includes behavioural decisions that are regarded as “free will” decisions — which presents no problem if one adopts a compatibilist interpretation of free will.

The above argument doesn’t fully rule out a minor role for genuine randomness based on quantum indeterminacy. I would guess that, were a quantum dice-throwing module within the brain of evolutionary benefit to an animal, then such a module could have evolved. But it’s hard to see why it would be evolutionarily beneficial. Just as we make technology to do what we want it to, genes will make brains that behave in ways they program for. That will hold especially for the large component of brain function that is simply about regulating body functions, not producing “behavioural choices”, and for the primitive brains producing fairly simple behaviour, such as in worms. This means that the neural-network junctions (synapses) will have evolved to be deterministic. This is achieved by a neural signal, an “action potential”, being an on–off event (so that it is insensitive to small changes), with a sufficient number of ions needed to trigger one (such that quantum indeterminacy is averaged over). This is pretty much the same way that humans make computer chips to be deterministic. Since larger and more complex brains work in a similar way, just with vastly more neurons and neural connections, it follows that they also will be deterministic.

Another point: our brains are simply too big and too complex to be about producing quantum “dice throwing” decisions. A device producing an indeterminate output would have to be small (again, averaging over anything more than a couple of dozen ions gives you a deterministic output). Yet our brains have 100 billion neurons made of 1026 molecules. What is all that for, and how did it evolve, if our decisions are effectively a dice throw? The only answer is that it evolved to process the information from our senses, and make decisions based on that, and making decisions based on input information is (by definition) a deterministic process.

Lastly, twin studies tell us that behavioural traits are highly heritable, with typical heritabilities of 50%. Again, this requires a causal chain between gene expression at the stage of brain development and behavioural choices made decades later. (There’s also a large role for the environment, of course, but being affected by environment is just as much a deterministic process as being affected by genes.)

Anyhow, I was told that I was wrong, and that quantum indeterminacy plays a role in our brains, especially when it comes to “free will”, and was pointed to a review paper arguing this by neurobiologist Björn Brembs of the Universität Regensburg.

Obviously a professor of neurobiology knows more about brains than I do, but, for now at least, I’m sticking to the above arguments. So what counters does Professor Brembs give? The paper first points out that the underlying physics is indeterministic. I agree, though, as above, that does not necessitate that brains are. The main argument presented, however, is the need for an animal to be unpredictable. Clearly, a gazelle running from a cheetah will benefit if the cheetah cannot predict which way it will dart. This will hold for any animal vulnerable to predation.

I agree on the need for unpredictability, but this does not require quantum indeterminacy. The world is simply way too complex for any of us to be able to predict it, even if that were “in principle” possible given enough information and intelligence. All that matters is that, in practice, predators stand no chance of making such predictions. The nematode worm (Caenorhabditis elegans) has only 302 cells in its nervous system. But even there, different individuals have those 302 cells wired up differently, owing to inevitable differences as the embryo developed. And if I gave you a complete map of the neural network of a mere 302 cells, could you look at it and predict how it would respond to various stimuli? I certainly couldn’t. The cheetah hasn’t a hope in hell of predicting the exact behaviour of the gazelle’s brain, even if that brain is entirely deterministic, and even if it had a complete and accurate neural-level map of that gazelle’s brain (which of course it doesn’t), and even if it had complete knowledge of the gazelle’s sensory experiences (which it also doesn’t).

So you don’t need indeterminacy to have in-practice unpredictability; the world is just too complex. And, while a prey animal wants unpredictability, it does not want to make dice-throwing decisions. There are some directions to dart — straight into the paws of the cheetah — that would be a rather bad choice. The gazelle still wants to make best use of all the information from its senses, and that requires a deterministic neural network.

And that’s about it: the above argument, that “predictability is one thing that will make sure that a competitor will be out of business soon”, and thus that “deterministic behaviour can never be evolutionarily stable” is pretty much the only argument that Professor Brembs presents for brains being indeterministic. He does argue at length for brains needing to produce “behavioural variability”, and that they need to flexible and adaptable and responsive to their environments. I agree entirely. But this is a separate issue from them being non-deterministic. Indeed, being responsive to their environments is itself a deterministic concept. The whole point of quantum indeterminacy is that it is not the result of anything, and so is independent of local conditions.

As an example, Brembs argues that:

“… the temporal structure of the variability in spontaneous turning manoeuvres both in tethered and in free-flying fruitflies could not be explained by random system noise. Instead, a nonlinear signature was found, suggesting that fly brains operate at criticality, meaning that they are mathematically unstable, which, in turn, implies an evolved mechanism rendering brains highly susceptible to the smallest differences in initial conditions and amplifying them exponentially. Put differently, fly brains have evolved to generate unpredictable turning manoeuvres.”

But sensitivity to small differences and a non-linear response is not the same thing as being non-deterministic. Deterministic systems often behave like that. A roulette wheel is non-linear and unpredictable in practice, even if it is deterministic. As another example, modern fighter jets are designed to be aerodynamically unstable, in order to be highly manoeuvrable — just like the fruit fly — and it would be straightforward to write a black-box computer code to produce a flight plan that another human (having no sight of the code) could not then predict.

I do wonder whether a rejection of determinism might be motivated by the false presumption that a “deterministic” response must inevitably be a simple, linear and inflexible response that is not responsive to the local circumstances? But this is not so. Responding to local circumstances is (by definition) a deterministic process, and behavioural variation and flexibility is exactly what you’d get from a complex but deterministic neural network.

But Professor Brembs wants a role for indeterminacy as an ingredient for his conception of free will.

While some argue that unpredictable (or random) choice does not qualify for their definition of free will, it is precisely the freedom from the chains of causality that most scholars see as a crucial prerequisite for free will.

I consider this to be misguided. As a compatibilist, I assert that the only “free will” that we have is entirely compatible with determinism. We have a “will” and often we are “free” to act on it. And yes, that will is indeed a product of the prior state of the system. The sort of “will” that arises independently of the prior state of the system does not exist (unless one wants to argue for dualistic souls that tell matter how to move).

But many people dislike that conclusion; they reject dualism but want to rescue a “will” that is “free from the chains of causality”. They hope that some mixture of causation and indeterminism might do that. Thus Brembs argues (as have others) for a “two-stage model of free will”:

One stage generates behavioural options and the other one decides which of those actions will be initiated. Put simply, the first stage is ‘free’ and the second stage is ‘willed’. […] freedom arises from the creative and indeterministic generation of alternative possibilities, which present themselves to the will for evaluation and selection.

This may be a failure of my imagination but I don’t see how this helps. Yes it gives freedom (from the causal chain) and it gives will, but the part that is free is not willed and the part that is willed is not free from causation. So it doesn’t give a “free will” if that is a will that is free from the causal chain.

The “free” part is simply generating a list of possibilities. The “will” part, the bit that is doing the choosing from the list, is still a computational process. Non-deterministic choice making could not have evolved.

Invoking the first stage serves only to salve an intuitive dislike of the idea that we are bound to the same processes of cause-and-effect that govern the rest of nature. People consider this to be beneath human dignity. But human intuition is unreliable, and a mechanism invoked purely to salve human dignity is unlikely to be how things actually are. If you think that a dice-throwing component is needed to generate options that could not otherwise be available, then you’re likely underestimating the degree to which the world is so complex that a deterministic neural network would already produce ample behavioural flexibility.

In short, I suggest that appealing to quantum indeterminacy in any discussion of free will is a red herring that has intuitive appeal but that cannot be made into a coherent account of a will that is uncaused. We should, instead, accept that there is nothing wrong with our wills being caused.

But it seems that Brembs is motivated by a dislike of the idea that we are at the end of a causal chain:

I hope to at least start a thought process that abandoning the metaphysical concept of free will does not automatically entail that we are slaves of our genes and our environment, forced to always choose the same option when faced with the same situation.

So what would be the problem if that were indeed the case?

In fact, I am confident I have argued successfully that we would not exist if our brains were not able to make a different choice even in the face of identical circumstances and history.

I don’t agree that the argument has been successfully made. And, anyhow, in practice, “identical circumstances and history” never recur. Walk around outside and look around you. The local environment that you are looking at is made up of something like 1032 individual atoms. That is so many that, if you were to point to them individually at a rate of one every second, it would take you 100,000,000,000,000 times the age of universe before you’d finished. The idea of “identical circumstances”, with every one of those atoms being in the same place and behaving the same way, is a valid philosophical thought experiment but is not of practical significance. The world already contains enough complexity and variation that there is no need to invoke quantum indeterminacy in order for a cheetah to be unable to predict the darting of a gazelle (if the cheetah counted neurons in the gazelle’s brain at a rate of one a second it would take it a mere 3000 years).

It makes no practical difference at all whether a different decision arises because of a quantum dice throw, or because the circumstances were slightly different. I don’t see why the former is preferable, or has more “moral” salience, or is more in accord with our human dignity (not that that actually matters; since the universe is not obliged to accord with our preferences).

Our Earth is not at the centre of the universe. The universe as a whole does not have a purpose. It was not created for us, we are just one product of an evolutionary process. And, being a product of the universe, we are material beings produced by and governed by the same laws of cause and effect that describe everything else.

29 thoughts on “Human brains have to be deterministic (though indeterminism would not give us free will anyhow)

  1. Dan Steeves

    The human brain is an absolute masterpiece of design. More complex than anything else in the universe. It is capable of expressing the wonderful spiritual qualities of love, wisdom, a sense of justice, a sense of artistic design and much more. There is no computer, nor will there ever be one, to even come close to the awesome wonders of the human brain. The brain is capable of understanding spiritual concepts. For instance, to ask why we are here and how we got here on planet earth. What happens when we die, why we die, and what hope is there for the dead and many more spiritual questions. The brain and the mind can only be the work of an awesome and infinitely wise Creator with the spiritual qualities that he endowed mankind with. There is no other reasonable nor scientific explanation.

    Reply
    1. Coel Post author

      I think that you are underestimating what could evolve through Darwinian evolution. I see no reason why the brain could not have done so.

    2. Dan Steeves

      Darwininan evolution has been laid to rest by true science. The 2nd law of thermodynamics and increasing entropy alone buries evolution. Those scientists who reason in a true scientific fashion have come to the very clear conclusion that evolution is a fake science. Read the list: http://www.dissentfromdarwin.org

    3. Coel Post author

      Thermodynamics (= “heat motion”) says only that the process of evolution would need an energy source. There is an energy source. It’s the sun.

    4. Dan Steeves

      The law of increasing entropy states that everything breaks down, wears out, rots etc. Therefore life on the cell level cannot come into existence by some misterious evolutionary force. And then evolve into millions of species of fish, reptiles, birds and mammals And then become progessively more complex until mankind (homo sapiens) comes into existence. EVOLUTION VIOLATES THE LAW OF INCREASING ENTROPY. A noted europian biologist once rightly called evolution “a fairy tale for adults.” Why do people swallow the darwinistic tale? Because for many decades people have been brainwashed to believe in it. Even to the degree that scientists who do not believe in evolution risk their scientific reputations But the tide is now turning as more scientists with very impressive credentials reject darwinism as the following list testifies. http://www.dissentfromdarwin.org

    5. Coel Post author

      The law of increasing entropy states that everything breaks down, wears out, rots etc.

      But that’s not what science says. If you’re going to invoke the authority of science in your arguments then you need to quote a scientific version of the 2nd law, which says only that processes of life need an energy input.

      Therefore life on the cell level cannot come into existence by some misterious evolutionary force

      There is no “mysterious force” involved, the processes of evolution by natural selection are well understood and well evidenced, and physics says only that the process needs an input of energy. That is provided by the sun.

    6. Dan Steeves

      The word ´selection´ and the verb ´to select´ indicates an intelligent process. For instance, people select the clothes they will wear, the car they will drive etc. So who does the selecting in ´natural selection´? The answer is NOBODY because ´natural selection´ is a fake science. Just like astrology is a fake science that people blindly believe in. But is it not true that people can be led to believe in absurdities and all the superstitious fakery peddled by this world? People swallow all the false promises that politicians peddle so that people vote for them. Catholics believe in and pray to dead images. And it´s all nothing more than propaganda. And that includes darwinistic evolution. No evidence in the fossil record that supports and proves evolution and evolution is NOT happening in the 21st century.

    7. Coel Post author

      The word ´selection´ and the verb ´to select´ indicates an intelligent process.

      You can’t make arguments from the meaning of human words, because that just tells you about human words, they don’t necessarily tell you how nature actually is. You’re right, nobody is doing is doing the selecting in “natural” selection. The whole point of the “natural” is that it is selection that happens automatically — that is, the next generation contains more of the genes that are better at propagating into the next generation simply because they are better at propagating into the next generation. (And the fossil record contains ample and abundant evidence supporting evolution.)

  2. Schlafly

    Your argument against free will is mainly saying that human actions must have some external cause. That is, external to human consciousness.

    This seems very similar to an argument for the existence of God. Something must have caused the world to exist. It is hard to see how the world could have caused itself to exist, so there must be an external cause. Call it God.

    Free will, and the rest of human consciousness, might be very surprising, except that it is so commonly experienced. Trying to convince me that I do not have free will is about like trying to convince me that I live in a simulation. It would negate the reality of all of my experiences, and instead say that I am a cog in a machine for which I have no evidence.

    Sam Harris buys into this free will denial to the extent that he says that he no longer has the feeling of free will. I suspect that he is damaged from taking too many mind-altering drugs. People without free will are not fully human. Based on his political opinions, he would probably be a Trump supporter if he had free will. But he is a slave to the voices in his head, I guess.

    Reply
    1. Coel Post author

      This seems very similar to an argument for the existence of God. Something must have caused the world to exist.

      I’m quite happy to accept that at a particle level things can just pop into existence. I don’t require a cause for everything. I’m ok with particle-level stuff being indeterministic. However, complex life, brains, that sort of thing, yes it needs a cause.

      Free will, and the rest of human consciousness, might be very surprising, except that it is so commonly experienced.

      Well, what is actually “experienced”? We experience ourselves having thoughts, desires, a will to do things. We do not “experience” where those things come from. We do not experience all the low-level machinery of the brain. It would utterly overload our experience to be aware of all those things. So we do not experience our will being uncaused, rather, the causes are outside of the range of things we experience, just as we’re not consciously aware of all the chemical reactions currently going on in our liver.

      Trying to convince me that I do not have free will is about like trying to convince me that I live in a simulation. It would negate the reality of all of my experiences, …

      But I don’t agree that your experiences tell you that your will is uncaused. Your experiences tell you only that you don’t experience the causes (or lack of causes) of your will

      … and instead say that I am a cog in a machine for which I have no evidence.

      But there is ample evidence for the existence of a vast neural-network brain/machine that is doing all sorts of information processing and creation of brain states. Despite our lack of conscious experience of the low-level workings of this machine, there is no doubt of its existence! And what else is it for if not to compute the end-product that we call our “will”?

  3. Schlafly

    You say “I don’t agree that your experiences tell you that your will is uncaused.” I don’t know what you mean by “uncaused”. If I make a decision out of my free will, then I am causing that. I am not arguing that anything is uncaused.

    Reply
    1. Coel Post author

      OK, so your “free will” decision is itself caused? Your “free will” is determined by your brain, so is effectively the output of a computation made by that brain, and that brain is itself the product of prior causes? If so, then you’re taking a compatibilist account (one I agree with). Or if you’re saying that your “free will” is not itself caused by the prior state, then you are arguing that something is uncaused.

  4. Schlafly

    If the brain makes a decision out of free will, then it originates in the brain. It is not determined by prior causes outside the brain. I would not call it uncaused, because the conscious mind is causing something to happen.

    I do not think that some purely philosophical argument about causality can possibly settle some question about the real world.

    Reply
    1. Coel Post author

      OK, so the “free will” decision is created by the brain, so it is determined by the prior state of the brain, and that prior state is determined by the state prior to that (along with sensory inputs)? Thus the brain is essentially a computational device. If so, then our “will” is caused by the physical stuff that generates that will.

  5. Schlafly

    You seem to be denying human consciousness as well. You say the brain is just a computational device. Okay, I guess I am arguing with a preprogrammed bot.

    Reply
    1. Coel Post author

      I’m not denying consciousness. It is part of what is generated by the material brain. You seem to see “consciousness” as something distinct from the material brain, that is not itself caused by material processes. That is pretty much a dualistic conception. While many people are intuitive dualists, it presents a whole host of philosophical problems.

  6. verbosestoic

    It follows that brains could not have evolved unless they were strongly selected for (they cannot just be byproduct “spandrels”), which means they must serve the interests of the genes that specify the recipe, and that means that brain behaviour (the choices they make) must be strongly influenced by the genes. And, since those choices can be being made decades after the childhood brain develops out of the genetic recipe, it follows that there must be a deterministic chain of causation that holds over generational timescales.

    This doesn’t actually follow. Evolution could very much be selecting for a capacity and so for something that ALLOWS for certain behaviours without needing to have any kind of genetic expression for those behaviours. Your argument is like saying that opposable thumbs had to have a benefit to evolve, and one of the things that opposable thumbs let us do is use tools, therefore there must be a genetic predisposition for tool-using behaviours. However, opposable thumbs grant the ability to use tools, and the environment makes it so that intelligent creatures like us will naturally come to the conclusion that using tools is a good thing even without any kind of genetic predisposition towards that behaviour. More importantly, if humans ended up growing up in an environment that DIDN’T support tool use — all the tools we could create are too brittle, for example, to do anything — then being able to grasp better might still be of benefit without appealing to that specific behaviour, even though humans would still be able to reason it out in cases where it IS beneficial.

    And this is going to be the case for the behaviours that relate to decisions and so to free will. Evolution would give us the CAPACITY to make decisions, but wouldn’t need to impose specific decisions and behaviours on us. In fact, doing that would seem to limit the actual benefit of giving us the capacity to make decisions, if the decisions we end up making are genetically determined. Moreover, we can tell the difference between instinctive behaviours and those that follow from genetic predispositions versus those that we reason out, and in fact one of the big things we need to preserve about decision-making is the ability for reasoning to override those sorts of behaviours. So if you reduce decision-making to those things in any significant way, it seems like you wouldn’t really be a compatibilist anymore [grin].

    Moreover, you don’t need to make that move. Compatibilism works perfectly well simply arguing that brain operations are deterministic without trying to make them determined in any strong way by genetics. Yes, some behaviours ARE genetically determined, but the ones that we would consider most “free” are the ones that clearly aren’t, and so are the ones that most need to be explained by a compatibilist.

    Reply
    1. Coel Post author

      Evolution would give us the CAPACITY to make decisions, but wouldn’t need to impose specific decisions and behaviours on us. In fact, doing that would seem to limit the actual benefit of giving us the capacity to make decisions, if the decisions we end up making are genetically determined. […] Yes, some behaviours ARE genetically determined, but …

      No-one is arguing that genes “impose specific decisions” or that behaviours are “genetically determined” (if that means that given Gene A then Behaviour X is inevitable). The claim is that behaviours are strongly genetically influenced. There are other strong influences. The local sensory information for example. The whole environment and set of experiences from conception onwards, for other examples.

      The whole point of neutral networks is that they combine all of these influences. The whole point (from the evolutionary point of view) is to produce novel and creative behaviours in any given situation, based on sensory information about that situation, but still being decisions that (in general) promote the genes’ interests.

      And twin studies tell us that behavioural traits are indeed strongly heritable, that is, our behavioural traits are strongly influenced by the particular package of genes that we, as individuals, got at conception. And, again, that must be the case since evolutionarily-expensive organs cannot evolve unless they are furthering the interests of the package of genes that created that organ.

      Evolution cannot produce an evolutionarily-expensive organ that gives us “the capacity to make decisions” if those decisions are then generally neutral from an evolutionary (propagation of genes) point of view.

      More importantly, if humans ended up growing up in an environment that DIDN’T support tool use — all the tools we could create are too brittle, for example, to do anything — then being able to grasp better might still be of benefit without appealing to that specific behaviour …

      For an opposable thumb and grasping behaviour to evolve there must have been something that it was evolutionarily advantageous to grasp (whether or not you want to call it a “tool”).

      Compatibilism works perfectly well simply arguing that brain operations are deterministic without trying to make them determined in any strong way by genetics.

      I’m not arguing this in order to support compatibilism, I’m arguing it because it seems to me that it has to be true, and because that’s what all the evidence (twin studies etc) points to.

    2. verbosestoic

      Evolution cannot produce an evolutionarily-expensive organ that gives us “the capacity to make decisions” if those decisions are then generally neutral from an evolutionary (propagation of genes) point of view.

      If the ability to make decisions is itself something that increases fitness — which it is, by allowing more reasoned and more complicated behaviours than we could get from instinctive or conditioned behaviours — then there need be no genetic link or genetic influence on the specific decisions THEMSELVES, and the specific decisions we make being strongly genetically influenced is what was at least implied by what you said. Again, in line with opposable thumbs being able to grasp things in any environment where there are things to grasp is beneficial enough without us having to have any kind of genetic predisposition to grasp any one of those things. No one will deny that we have genetically predispositioned behaviours such as instincts, and twin studies talk about those sorts of things like broad personality traits. But those sorts of things actually are less important and so have less influence in the sorts of decision-making that are most indicative of free will, and so in the context of this article don’t play much of a role. The key factors in free will come into play in those cases where twins WOULD or COULD choose differently than each other, not in the cases where they in general would choose the same.

      So I don’t really understand what you mean when you talk about behaviours being strongly influenced by genetic factors and so selected for in the context of a discussion around free will. Decisions will be precisely those things that are LESS influenced by genetics and so aren’t specifically selected for, and so are selected for entirely on the basis of the capacity and not the specific behaviours they produce.

    3. Coel Post author

      If the ability to make decisions is itself something that increases fitness — which it is, by allowing more reasoned and more complicated behaviours than we could get from instinctive or conditioned behaviours …

      But the ability to make more complex decisjons can only increase fitness if the resulting decisions do increase fitness rather than decrease it. Thus a more complex “running from a cheetah” behaviour can be favoured, but only if the more-complex running pattern leads to more escapes. “Making decisions” would not be favoured if the decisions tended to be “nah, I’ll just stay here and get eaten”.

      The key factors in free will come into play in those cases where twins WOULD or COULD choose differently than each other, not in the cases where they in general would choose the same.

      How are you defining “free will”? And is that claim true by definition (“it wouldn’t be free will if the genetically-identical twins tended to make the same decision”)?

      So I don’t really understand what you mean when you talk about behaviours being strongly influenced by genetic factors and so selected for in the context of a discussion around free will.

      I don’t think there is any “free will” that is other than the decisions that we make that (I assert) arise from the deterministic computations of a neural-network brain. I certainly don’t think there is a “free will” that is distinct from the neural-network computational outputs. And no-one has put forward a proposal for how any such thing would work.

    4. verbosestoic

      But the ability to make more complex decisjons can only increase fitness if the resulting decisions do increase fitness rather than decrease it. Thus a more complex “running from a cheetah” behaviour can be favoured, but only if the more-complex running pattern leads to more escapes.

      Well, sure, decision-making only increases fitness if in general we make GODD decisions rather than BAD ones, but our considered decision-making processes will in general improve fitness because they allow us to override instinctive or conditioned behaviours that would in general be beneficial but due to specific conditions or long-term interests aren’t good in a specific case. To take your running away example, running away from cheetahs in general would be likely to end up as an instinctive or conditioned response because it clearly works in general, but when you are in a group of people with weapons and want to chase it away from your livestock or harvest its fur for clothes decision-making processes that let you know that in this case it’s not a threat would be beneficial. So, as I noted, decision-making processes are at their most beneficial in cases where instincts and genetic preconditions are being overridden by them, and so those cases are more indicative of the benefits decision-making gives us and so are the cases that most define what decision-making — and thus, free will — cases are, and so the details of those cases most characterize free will. And so talking about the influences of genetic predispositions on specific behaviours in the context of free will is talking about specifics that LEAST characterize and so are least relevant to a discussion of free will.

      How are you defining “free will”? And is that claim true by definition (“it wouldn’t be free will if the genetically-identical twins tended to make the same decision”)?

      Free will behaviours are defined by anyone who thinks that free will exists at all as being those that follow from our decision-making processes, which consider the specific circumstances and all of the desires and beliefs of the agent. The cases where twins most act like each other are cases where the decisions follow from instincts or from personality, which are the exact cases that we want our decision-making processes to override. For example, if twins both were shy they would likely decide things out of shyness at about the same rate, but the key would be if they act against that shyness due to considering that in a specific case it wouldn’t work for them. The differences in the lives of twins all follow from those specific instances and cases, and so from the individual decisions they made. So twins themselves provide evidence for the ability of our decision-making processes to change outcomes and behaviours because all of their differences follow from that. I don’t need to deny that they have similar genetic predispositions and instincts to say that, nor do I need to deny that decision-making is deterministic. All I need to question is whether a strong influence from genetics towards the specific behaviour is really indicative of behaviours that follow from our decision-making processes or not.

      I don’t think there is any “free will” that is other than the decisions that we make that (I assert) arise from the deterministic computations of a neural-network brain. I certainly don’t think there is a “free will” that is distinct from the neural-network computational outputs. And no-one has put forward a proposal for how any such thing would work.

      I don’t see how this in any way answers my question about the role of genetics in producing the specific behaviours that we feel result from our decision-making processes and so are considered free choices in the context of free will. It more sounds like you’re trying to argue against a libertarian view (that you probably remember I have) than in explaining what you yourself mean in this case, because it does seem to me that compatibilist views can hold that our decision-making processes are determined and yet that genetic predispositions aren’t, in general, prime examples of that or a major factor in the decisions that are produced. In fact, I’d argue that doing that is pretty much REQUIRED for compatibilism, since it allows them to carve out free choices from ones that aren’t produced by our decision-making processes, and genetic predispositions aren’t produced by those processes by definition (and while conditioned responses can be, they exist precisely because they short-circuit those processes in order to decrease response time).

    5. Coel Post author

      but our considered decision-making processes will in general improve fitness because they allow us to override instinctive or conditioned behaviours

      But “decision-making” can never be abstract, it is always about aims and goals. So more-considered decision making will only benefit if it is advancing genetic interests.

      So, as I noted, decision-making processes are at their most beneficial in cases where instincts and genetic preconditions are being overridden by them, …

      But, as above, beneficial decision-making processes are just as much about genes and their interests as simple, pre-programmed behaviour. That’s why genes build the brain. It’s wrong to see these as separate or competing processes, the higher cognitive functions are just a more-complex version of the lower ones.

      Free will behaviours are defined … as being those that follow from our decision-making processes, which consider the specific circumstances and all of the desires and beliefs of the agent.

      That’s exactly what a deterministic brain would do, where the brain is strongly influenced by the genes, but also weighs up sensory inputs. So it considers the circumstances and its own interests and computes the best choice.

      Indeed, a chess-playing computer has “free will” under your definition. So if you didn’t intend that, then your definition isn’t clear.

      … the key would be if they act against that shyness due to considering that in a specific case it wouldn’t work for them.

      Yes, but genetic influence isn’t (effectively) “shyness and nothing else”, it is “shyness and all sorts of other things”, and it’s those other things — that are also genetically influenced — that operate to override the shyness.

      it does seem to me that compatibilist views can hold that our decision-making processes are determined and yet that genetic predispositions aren’t, in general, prime examples of that or a major factor in the decisions that are produced.

      Yes, I agree. A compatibilist could, in principle, be a blank-slateist (decisions are determined, but entirely by the environment and culture). So I’m not arguing for the role of genes in order to be a compatibilist, I’m arguing it in order to be consistent with evolution and twin studies and biology in general.

      since it allows them to carve out free choices from ones that aren’t produced by our decision-making processes, and genetic predispositions aren’t produced by those processes by definition …

      Again, I don’t think we should look at this as though there are different decision-making processes, with “free will” ones being distinct from “genetic predispositions”. The whole point of neural networks is that all the influences combine together in a hugely complex and inter-twined way.

    6. verbosestoic

      Sorry for the delay in replying. As usual I go on vacation and don’t get around to commenting as much as I should.

      But “decision-making” can never be abstract, it is always about aims and goals. So more-considered decision making will only benefit if it is advancing genetic interests.

      I’m ultimately very puzzled about what you mean by “advancing genetic interests”, especially when you try to talk about advancing goals here. The entire point of evolution is that we can have selection for beneficial traits and the weeding out of detrimental traits WITHOUT anything having a specific goal of enhancing genetic fitness. Talking about goals here confuses the issue even more because the decision-making processes that we are considering here have as a beneficial trait the ability to specifically pursue and even set goals, which allows for more complex behaviour and societies. So the entity is setting goals for itself, and that increases fitness since it can more directly react to the world. We don’t need any kind of specific genetic instinct or instinctive goal to really achieve that.

      I also find it odd that you here talk about things not being able to be that abstract and yet you keep ignoring specific cases and not providing any specifics yourself. I think things would be a lot more clear if you would point to specific examples of what you mean.

      But, as above, beneficial decision-making processes are just as much about genes and their interests as simple, pre-programmed behaviour.

      This is a prime example of the problem. What do you mean when you say that they are just as much about the genes? Instinctive behaviours are programmed BY the genes, and decided behaviours have the huge benefit of overriding those genetically programmed behaviours. So THAT can’t be what you mean, but I’m at a loss to understand what you DO mean here.

      Indeed, a chess-playing computer has “free will” under your definition. So if you didn’t intend that, then your definition isn’t clear.

      Well, recall that I’m a libertarian about free will and a software designer. My argument that the chess-playing computer does not have free will is NOT based on that its behaviour is not context-sensitive, but that it’s not SEMANTICALLY-sensitive. In short, it can react to an input but doesn’t understand what that input means. So I don’t claim that it doesn’t act on “data”, but that it doesn’t understand what that data really is, which follows from it being overly deterministic because it doesn’t really have semantics. This is also why I reject a brain model because neural nets clearly DON’T have semantics and only react to the forms of the inputs, in the same way as the Chinese Room does. So my definition TO THAT END is still valid and it’s another reason or part of the full definition that would make the difference here, so that doesn’t call my definition into question at all.

      Yes, but genetic influence isn’t (effectively) “shyness and nothing else”, it is “shyness and all sorts of other things”, and it’s those other things — that are also genetically influenced — that operate to override the shyness.

      But this only dodges the example, which is again contributing to things not being clear. Shyness is a different type of genetic influence than decision-making is, mostly because shyness is a direct program while the results of decision-making are not AND have the huge benefit of being able to override those sorts of programming when the specific cases warrant it. What twins have in common are those programmed responses, but their lives will indeed be quite different based on the individual decisions they make. YES, decision-making ability is genetic but that doesn’t mean the results it produces are genetically influenced to the degree you seem to need it to, and so again I haven’t a clue what sort of influence you are talking about here.

      Yes, I agree. A compatibilist could, in principle, be a blank-slateist (decisions are determined, but entirely by the environment and culture). So I’m not arguing for the role of genes in order to be a compatibilist, I’m arguing it in order to be consistent with evolution and twin studies and biology in general.

      I suspect that you’re operating on a false dichotomy here, arguing that your opponents think that there cannot be ANY genetic influence whatsoever or else genetics plays a huge role in it. To use the shyness example, shyness would be a consideration in the decision-making process but the decision-making process by definition can overcome that sort of consideration to make a choice based on the specifics of the here and now, which is its genetic benefit that had it be selected by evolution. So someone can accept all influences without prioritizing one of them. Again, I am at a loss as to what influence you think the genes must have in specific decisions, and if you don’t think that then your argument doesn’t seem to be responding to anything anyone opposed to you actually believes.

      Again, I don’t think we should look at this as though there are different decision-making processes, with “free will” ones being distinct from “genetic predispositions”.

      Genetic predispositions like instincts AREN’T decision-making processes, because they are simple stimulus-response mechanisms. Decision-making processes are those precise processes that can act on a consideration of conditions rather than merely as responses. Instincts are clearly more akin to reflexes than decisions, and reflexes are strongly deterministic but also do not consider conditions. When the doctor hits your knee, your knee reflexively extends even when it really shouldn’t. Decisions have benefit precisely because they in theory don’t produce those sorts of behaviours when they shouldn’t be produced.

    7. Coel Post author

      Hi verbose,

      I’m ultimately very puzzled about what you mean by “advancing genetic interests”, …

      I mean that the decisions that the brain makes must (in general) be ones that enhance the likelihood of the genes propagating to the next generation. They cannot be neutral w.r.t. that, nor (in general) ones that reduce the likelihood of gene propagation.

      I think things would be a lot more clear if you would point to specific examples of what you mean.

      As an example, the gazelle’s darting behaviour when chased by a cheetah must reduce its chances of being eaten. A more complex brain producing more-complex behaviour cannot evolve, unless the resulting decisions (in general) increase the likelihood of survival and reproduction.

      What do you mean when you say that they are just as much about the genes? Instinctive behaviours are programmed BY the genes, and decided behaviours have the huge benefit of overriding those genetically programmed behaviours.

      I’m saying that it is wrong to suppose that there are two types of behavioural decision, simple ones programmed by genes, and then more-complicated ones where the genetic programming gets over-ridden.

      *All* of the decision making is strongly influenced by genes. So, one should think of simple decision-making programmed by genes, and more-complicated decision-making which is just as much genetically influenced and just as much about the interests of the genes.

      Indeed the whole point of brains is that the genes provide an instruction recipe to build a brain precisely because the more-complex decision making, taking more factors into account, will do a better job of propagating the genes to the next generation.

      It is very wrong to suppose that genetic influence is only about simple and predictable behaviour. Complex, human decision making is also strongly influenced by our genes. All behavioural traits are heritable.

      My argument that the chess-playing computer does not have free will is NOT based on that its behaviour is not context-sensitive, but that it’s not SEMANTICALLY-sensitive. In short, it can react to an input but doesn’t understand what that input means.

      Here you are doing the typical philosopher’s thing of wrapping every issue up with consciousness and declaring that X doesn’t count as X unless one is doing a conscious self-reflection on X and thus is self-aware that one is doing X.

      Personally I think that’s a completely unhelpful way of thinking!

      This is also why I reject a brain model because neural nets clearly DON’T have semantics and only react to the forms of the inputs, in the same way as the Chinese Room does.

      Well this is a whole ‘nother issue, but it is not clear to me that a neural network (or a Chinese Room) is necessarily deficient in semantics.

      Shyness is a different type of genetic influence than decision-making is, mostly because shyness is a direct program while the results of decision-making are not …

      I don’t agree with your attempts to divide “direct” (genetic?) programming from higher-level decision making. The whole point of a neural network is that it mixes all influences up in a highly entangled way. Anyway, the “shyness” of a child is very context dependent and can change on hourly timescales, so is also a high-level behavioural choice.

      What twins have in common are those programmed responses, …

      Again, it is very wrong to distinguish simple “programmed” responses from higher-level decision making. *All* decision-making is strongly genetically influenced.

      YES, decision-making ability is genetic but that doesn’t mean the results it produces are genetically influenced to the degree you seem to need …

      But they are! That’s what the data tell us. For example, which political party one votes for is strongly influenced by genes. So are all other, similar, high-level behaviours.

      … so again I haven’t a clue what sort of influence you are talking about here.

      As just stated, things like which political party one votes for is strongly influenced by ones particular genes. So is all complex, high-level behaviour.

      Genetic predispositions like instincts AREN’T decision-making processes, because they are simple stimulus-response mechanisms.

      Wrong! You are *wrong* to see genetic influence as only about hard-wired instinctive responses. It’s also about all other aspects of behaviour and personality.

      Genetic influence is thrown into the neural-network mix along with development, past experience and sense data.

      Decisions have benefit precisely because they in theory don’t produce those sorts of behaviours when they shouldn’t be produced.

      Which is exactly why genes build brains to combine and entangle genetic influences with sense data and other influences. Thus, how someone responds to being hit — whether they hit back, or run, or take it stoically without retaliating — will depend a lot on their genes, and on their past experiences and socialisation and on the specific context. But the likelihood of each response is strongly affected by ones particular genetic package.

  7. Schlafly

    I would expect that a conscious human with free will would have an evolutionary advantage over deterministic humans. The deterministic human would be like a pre-programmed robot, and lack the ability to adapt to new situations. The conscious humans would be likely to see the deterministic humans as slaves, and not worthy of taking part in a civilized society.

    Reply
    1. Coel Post author

      The deterministic human would be like a pre-programmed robot, and lack the ability to adapt to new situations.

      I don’t agree that that would be the case. The common intuition that “determinism” must mean simple, fixed and predictable behaviour is not true. The whole point of neural networks (created by genes in combination with a developmental learning program and taking input data from the senses) is to create novel and creative behaviour in a given situation.

      If human “free will” did give an advantage here, how come — for example — that deterministic, neural-network chess-playing computers can completely out-think humans nowadays? Even the best grandmasters nowadays stand no chance against neutral-network engines such as Alpha Zero.

      And also, how can you assert that having “conscious free will” gives an advantage when you’ve given no account of how this works? You don’t accept that a “conscious free will” decision is generated by and results from the prior state of the material brain, and yet you’ve also said that you don’t regard anything as being “uncaused”.

  8. Schlafly

    Yes, the chess computers can out-think humans, but only at the chess board.

    You are right that I cannot give a mechanistic deterministic account of how free will works. It would not be free will, if I could.

    The latest Quillette podcast has Sam Harris ranting against free will. He appears to be ruled by the voices in his head.
    https://quillette.com/2022/03/25/sam-harris-on-islam-dropping-acid-joe-rogan-vaccine-pseudoscience-the-wonders-of-meditation-collaborating-with-ricky-gervais-and-the-myth-of-free-will/

    Reply
  9. Robin Herbert

    To me it comes down to what a person means by free will. As far as I can see, most people see it as a question of substitutability and agency, ie:

    “A person has libertarian free will iff there are at least some occasions that, when a person is consciously deliberating on a future choice that:

    1. The outcome is not already inevitable and;
    2. The conscious deliberation is at least a proximate cause if the outcome”

    If people mean something else by free will then I don’t know what they mean by it.

    If they do mean this then substitutability due to there being randomness satisfies the definition just so long as the deliberation is long enough.

    If libertarian free will due to randomness does not seem like free will then the problem is in the definition. So we would have to come up with a new definition, one which is not satisfied by there being some randomness in our brains.

    To me the problem of free will is that no one really knows what they mean by it and probably that means we don’t really mean anything by it, so it is not worth worrying about.

    Reply
    1. Coel Post author

      I would largely agree with you. As I see it, in the only form of “free will” that exists, the “freedom” is a socially constructed concept and is about the social freedom to act on ones will, it is not about the will being “free” in the sense of uncaused.

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