What Do People Find Incompatible with Causal Determinism?
By Adam Bear
Imagine a universe in which everything that happens is completely caused by whatever happened before it. This is true from the very beginning of the universe, so what happened in the beginning of the universe caused what happened next, and so on right up until the present.
Philosophers have long debated whether a causally deterministic universe like this one poses a threat to free will and moral responsibility. For example, suppose that in this universe a man murders his spouse. Everything that has come before this (e.g., the man’s upbringing, his parents’ decision to pass on their genes, his past experiences with his spouse) fully determined that he would commit this murder. Given this, is it still reasonable for us to blame him for his crime?
Recently, social psychologists have joined the discussion, exploring how ordinary people think about these questions. In particular, if people think that they can’t be held morally responsible for their actions in a deterministic universe, then inducing them to believe that they live in such a universe might also encourage them to behave in morally dubious ways. This seems to be the case: making people believe that our universe is deterministic causes them to cheat more, feel less retributive, and help others less often. One study even finds that these attitudes about moral responsibility in a deterministic universe depend on whether you’ve been given a dose of the hormone oxytocin!
A conclusion of much of this work is that ordinary people think it’s impossible to be morally responsible for one’s actions in a causally deterministic universe. But perhaps there is more to the story. Maybe in addition to thinking that you can’t be morally responsible for your actions in such a universe, people think that you couldn’t even do certain things in the first place. Consider again the man who murders his spouse. We have assumed that this murder, and the chain of events that led up to it, could have occurred if everything were causally determined. But perhaps ordinary people think differently. Perhaps they think that certain parts of the causal chain leading up to this murder could not even unfold if everything were determined because certain behaviors require indeterminism.
In a recent paper published in the journal Cognitive Science, Joshua Knobe and I explore this question. We presented a nontechnical description of a causally deterministic universe to participants and then asked whether various behaviors were possible in this universe. Could people fall in love? Carry on complex conversations? Think twice about committing an immoral act? Resist the urge to eat a juicy steak?
We found that some behaviors were almost universally judged to be possible. For example, people thought that, in this universe, you could imagine a purple square, compose a complicated piece of music, and fall in love. But people were more skeptical about other behaviors. For example, our participants tended to believe that you couldn’t think twice about doing something immoral, decide not to go to a party in order to study for an exam, or resist the urge to eat a steak.
Even on its own, this result is quite surprising. Researchers have long suspected that causal determinism could undermine various abstract goals of assigning praise, blame, and so on to people’s actions. But, for the most part, these researchers have not considered whether determinism could also pose a threat to the ordinary ways in which we understand these actions in themselves. The fact that our participants thought that you couldn’t even do certain things in a deterministic universe suggests that people regard indeterminism as a fundamental prerequisite of normal human behavior.
Given that people think that certain behaviors are impossible to perform in a causally deterministic universe, a further question arises about what makes these impossible behaviors unique. Interestingly, some of these behaviors seemed to require willpower (e.g., resisting the urge to eat a steak), while others seemed to occur effortlessly and spontaneously (e.g., impulsively shoplifting from a convenience store).
To capture the wide range of behaviors thought to be incompatible with determinism, we introduce a psychological concept that is perhaps best summed up by the Queens of the Stone Age song “Go with the Flow”. Intuitively, it seems that certain of our behaviors involve just passively “going with the flow” whereas others might be thought to require taking initiative and “breaking off from the flow of things”. For example, a person who just goes to the same boring nine-to-five job day after day might be thought to be going with the flow. In contrast, this person could break off from the flow of things by, say, pushing herself to work especially hard one night and stay in the office past midnight or by suddenly deciding to quit her job to join the circus. In other words, there seem to be two broad ways in which a person could go against the flow: by using willpower or by acting spontaneously.
Josh and I hypothesized that it was precisely these types of behaviors, which might be seen to involve working against the ordinary causal forces of the universe (the causal “flow”), that our participants would find incompatible with causal determinism. For, if an event that occurs in a causally deterministic universe is fully caused by whatever happened before it, there is no opportunity for a person to work against these forces and break off from the flow of things.
Our studies supported this conjecture. First, people thought you could go against the flow in both of the ways we predicted—by exerting willpower or by doing something spontaneous. So a person who resisted the urge to eat a steak was judged to be going against the flow, but so was someone who impulsively shoplifted from a convenience store. More importantly, the behaviors participants thought involved breaking off from the flow of things, taking initiative, or seizing control of a situation were precisely the behaviors they thought were impossible in a deterministic universe. In other words, the notion of going with the flow is more than just a silly colloquialism used in rock lyrics; it reflects how people reason about the psychological forces motivating human action.
Philosophers and psychologists have long considered how causal determinism might threaten our commonsense views about moral responsibility. But perhaps this focus has been too narrow. Maybe it isn’t just moral responsibility that people feel is threatened by determinism, but the prospect that we could even perform certain behaviors in the first place. If this is the case, we all may need to fundamentally rethink how we think about determinism.