Incompat notebook
Created 17 Aug 2025 • Last modified 11 Apr 2026
Interviewing
Premise
What's going on in the heads of all those people who believe in incompatibilist free will, anyway? You could try some informal interviews to get hypotheses about how people think this—and perhaps how they might be persuaded otherwise.
IRC reminders
- To make an account,
/nick Kodiand/quote ns register PASSWORD - To log in as the interviewer,
/quote ns identify Kodi PASSWORD - To register a channel,
/quote cs register #interviewing - Use
/mode #interviewing +l 2so that other users can't peek on the conversation - Save all chat history via Ergo's debug log
Questions
Interest check
I've been conducting some informal interviews for a research project. The topic is people's beliefs about free will. Are you interested in being a subject?
Consent check
This interview is being conducted as part of a research study about free will. I, the researcher, am Kodi B. Arfer; you can find contact information for me at https://arfer.net/elsewhere . If you decide to participate, then you retain the right to change your mind and leave the study at any time without giving any reason, and without penalty.
If I distribute transcripts of or quotations from this interview, they will be deidentified, meaning that I'll exclude identifying information like your Prolific user ID. Do you consent to being in this study?
Content
First question. Imagine some physical process playing out, like a billiard ball bouncing around a table. If we consider the entire past and present of the universe up to this point, and the laws of nature, do you think that those two, taken together, are enough to determine exactly what the billiard ball will do?
[If quantum stuff comes up:] Ultimately I think quantum stuff is a distraction from the kind of philosophical issues I want to examine in this interview, so for the sake of argument, let's assume that a hidden-variables theory of quantum mechanics is true, meaning that quantum events aren't random.
[Subjects may also confuse the issue of predictability with the issue of determinacy, as in the case of subject 4. You could say:] Keep in mind that I'm really asking about determinacy, not predictability. My question isn't whether one could, in practice, predict these things. My question is whether there's only one possible outcome once these other things (the past and present of the universe, the laws of nature) are held fixed.
Now let's consider a similar question but with an animal instead of a billiard ball. Do you think the past and present of the universe, and the laws of nature, would also be enough to determine the actions of an animal, like a goldfish? We could put the goldfish in a decision-making or maze-running task, for example.
["Bypassing", in the sense of Murray and Nahmias (2014), may also come up. This is when people interpret determinism to imply bypassing of mental states in causal chains.]
[Then, humans.]
Interview summaries
N.B. Subjects 1 through 4 are people I knew personally.
Subject 1
Here I started off by asking about human decision-making. S said that to believe that human decisions are deterministic would be to believe in a higher power, which he doesn't. I decided that for future interviews, I'll start off with questions about a physical process and build up towards human decisions.
Subject 2
Putting quantum issues aside, S said that human decisions are deterministic.
Subject 3
Putting quantum issues aside, S said that human decisions are deterministic. He postulates a supernatural influence, which is the karma created by previous people's decisions, but argues that the result is still deterministic. This interview got a bit too mired in quantum issues, which are beside the point of this study, so for future interviews I'll have a standard response ready to try to get them out of the way if they come up.
Subject 4
I think S ultimately admitted that human decisions are deterministic, but there was confusion between predictability and determinism, which I should've addressed earlier in the interview. My research interest here is why people believe that human actions are genuinely indeterminate, not merely unpredictable in practice. Of course, per Murray and Nahmias (2014), perhaps most people don't really believe this.
Subject 5
S looks to be incompatibilist, but ultimately seemed to fail to articulate why she believed this or how it jibes with her idea that events are brought about by conditions. I probably could've asked better questions here, but I have little idea of what better questions would be.
Subject 6
S initially denied that physical processes were deterministic, but changed their mind and acknowledged that physical processes are deterministic once we got deeper into it. For animal and human action, S again started off saying no, but ultimately at least entertained the possibility that these two are deterministic, without outright saying they believe it.
Subject 7
S allowed that human decisions are deterministic. He referred to Sam Harris's book Free Will, so he may be more familiar with related concepts than the average person. Then again, Sam Harris is the kind of writer on philosophy who ignores, and largely won't discuss, mainstream philosophy.
Subject 8
Eventually S appeared to allow that human decisions are deterministic, but we didn't have time to get into questions about humans, since we ran long on the fish step of the interview. I think a primary difficulty here is that S was unwilling to play along with a conventional definition of the word "deterministic": I had to use a circumlocution to make progress.
Subject 9
S looks to be a committed non-physicalist, postulating a force of consciousness that is necessary for decision-making in humans as well as animals, which makes organismal behavior non-deterministic. Surprisingly, S is an atheist and doesn't consider this supernatural.
Subject 10
S asserted that human action is deterministic with the least hesitation I've seen so far. She is compatibilist, saying that "free will is about that lived experience of choosing and reasoning for myself".
Conclusion
I now suspect Murray and Nahmias (2014) was right and most people don't really believe in incompatibilist free will. They just get confused by philosophical definitions, or fail to think things through, and end up sounding incompatibilist. There certainly exist some people who are incompatibilist, but I think my interest is more in typical lay philosophy than in this minority population.
Empirical study
To test this idea more seriously, let's try a study in which I examine how people's answers to question about free will differ (either between-subjects or within-subjects; within-subjects may be more interesting from the persuasion point of view) when they're asked other questions or given other information that I believe will get them to think more deterministically.
Imagine
- time-1 measure of incompatibilism
- intervention (perhaps a tree of multiple-choice questions modeled after the interview)
- time-2 measure of incompatibilism
If all subjects get this procedure, it's not a true experiment, but maybe randomly assigning an intervention to compare it to a no-treatment control isn't so interesting here (since we assume that under no treatment, the subject won't change his mind so quickly). But it could be nice to have a control that allows us to compare the effect of the main intervention to subjects just wanting to change their mind to appease the experimenter. The trick is that it's unclear how to design such a control intervention. I guess that in the name of simplicity, I should begin without a control; if I can't get a difference from time 1 to time 2, then I don't need a control to see that the intervention has failed.
Some relevant reading:
- Murray, Dykhuis, and Nadelhoffer (2022): Shows how people may fail to consider the concept of determinism as intended when being asked questions about philosophical vignettes.
- Nadelhoffer, Murray, and Murry (2023): Shows how people may fail to understand determinism. Subjects were asked to consider some deterministic universes, and most subjects indicated in their responses that they had confused the situation with predestination or something like that.
- Cova and Martinez (2025): Study 4, surprisingly, compared MTurk to Prolific. It found that MTurk users seem to just choose randomly (favoring the right-hand side of each scale) in these philosophical experiments. Overall, on the basis of 5 studies, Cova and Martinez argue that measures that were supposed to capture certain kinds of misunderstanding of determinism or vignettes fail to do so. In study 5, which was most careful to get subjects to understand determinism, subjects were about evenly split in their belief that real life is deterministic.
Discarded text bits
You can also think of the ball's movement as being influenced by general principles, or physical laws. For example, gravity influences the movement of the ball, and how gravity works is described by laws of physics. Other fields of science can be relevant, too. For example, biology is involved in how I ended up with the exact muscle mass I have, and hence influences how hard I hit the ball. Let's call this set of possible influences the laws of nature.
[new page]
Quiz time. Given these definitions, the positions of other balls on the table, and how they influence where my ball goes, are part of
[ ]the complete situation[ ]the laws of nature
[new page]
Right. And the equations governing how a moving object is deflected when it hits another object are part of
[ ]the complete situation[ ]the laws of nature
Results
N.B. Subjects 1 and 2 are people I know personally.
Aggravatingly, even with the educational text and quizzes, it seems that people aren't properly understanding the first important question, opinion_deter_billiards, judging by the explanations they provided. I can always try to improve the educational process, but I can't make subjects put enough effort into understanding. Both of the common confusions about determinism that I specifically tried to address—determinism versus predictability and determinism versus causation—seem to have been a problem for opinion_deter_billiards. In commit f0c237b4ea41c3b329f842d52c19b061f395fecf, I added a follow-up question to address one specific sort of misunderstanding, and that doesn't seem to have helped, either.
References
Cova, F., & Martinez, T. (2025). Failure to comprehend determinism or failure to measure comprehension? Methodological issues in experimental philosophy of free will. Erkenntnis, 90(7), 3215–3253. doi:10.1007/s10670-024-00844-1
Murray, D., & Nahmias, E. (2014). Explaining away incompatibilist intuitions. Philosophy and Phenomenological Research, 88(2), 434–467. doi:10.1111/j.1933-1592.2012.00609.x
Murray, S., Dykhuis, E., & Nadelhoffer, T. (2022). Do people understand determinism? The tracking problem for measuring free will beliefs. doi:10.31234/osf.io/kyza7
Nadelhoffer, T., Murray, S., & Murry, E. (2023). Intuitions about free will and the failure to comprehend determinism. Erkenntnis, 88(6), 2515–2536. doi:10.1007/s10670-021-00465-y