The Big Short

Rationality Tie-in: 

This is a film about the 2008 Financial Market Crash, and tells the stories of...

The Big Short is the filmic equivalent of my spirit-animal.

Rationality writings it is connected to: 

I thought this would be hard, but actually it ties into so much.

Smallfoot. It's a children's animated musical about yetis who don't believe in humans, and about fraud and honesty and curiosity and how other motives, even sympathetic ones, contaminate truthseeking.  Hat tip to Elizabeth of Aceso Under Glass who recommended it to my family.

Prelude to Power is my favorite depiction of scientific discovery. Unlike any other such film I've seen, it adequately demonstrates the inquiry from the perspective of the inquirer, rather than from conceptual or biographical retrospect.

The Truman Show: Great depiction of crisis of faith, noticing your confusion, and generally is about figuring out the truth.

Most relevant sequence posts: Crisis of Faith, Lonely Dissent

Baraka: A guided meditation exploring the human experience; topics like order/chaos, modernity, green vs. other mtg colours.

More than "connected to something in sequences" it is connected to something which straw sequence-style rationality is prone to miss. Writings it has more resonance with are Meditations on Moloch, The Goddess of Everything Else, The Precipice.

There isn't much to spoil: it's 97m long nonverbal documentary. I would highly recommend to watch on as large screen in as good quality you can, watching it on small laptop screen is a waste. 

Film: The Martian

Rationality Tie-in: Virtue of scholarship is thread throughout, but Watney is generally an intelligent person tacking a seemingly impossible to solve problem.

Jan suggested a similar one (Baraka), but I was going to say Koyaanisqatsi. It’s one of my favorite films; I still feel deeply affected by it. I bring it up here, though, because it does an excellent job of inviting viewers to do original seeing. It’s basically a 90 minute documentary about the world, but it doesn’t feel like it has any agenda. It’s just shot after shot of what this planet is like (the Grand Canyon, a commute to work, a factory farm). It doesn’t shy away from anything, doesn’t feel like it’s grasping at some goal. Just an honest, gentle look at what the world is like, and what humans are up to.

Part of the reason I say that it’s good at inviting original seeing is that it does a really excellent job of perspective modulation (especially wrt time). E.g., it’ll slow down or speed up processes in ways that made me pop out of how I normally relate to them. It lingers on features I wouldn't normally wouldn’t linger on (like someone’s face) which turned it into this entirely new and strange experience. In general, it takes the mundane and makes it into something kind of glorious—a piece of the world to be marveled at, to be wondered at, a thing to be curious about.

But it’s not just mundanity either; it reminds you that you’re in a vast universe, on a planet that not too long ago didn’t contain you. It starts with a close up of a cave painting, and it ends with this haunting scene of a rocket falling down to Earth. And I remember really grokking, at the end of it, just how strange and just how powerful a thing intelligence is—the magnitude of what we’ve accomplished. I’d had that feeling before, but something about it really stayed with me after watching this film.

I Am Mother

Rational protagonist, who reasons under uncertainty and tries to do the right thing to the best of her knowledge, even when it requires opposing an authority figure or risking her life. A lot of focus on ethics. 

The film presents a good opportunity to practise noticing your own confusion for the viewer - plot twists are masterfully hidden in plain sight and all the apparent contradictions are mysteries to be solved. Also best depiction of AI I've seen in any media. 

12 Angry Men

Connection to rationality: 

This is just the perfect movie about rationality.  Damn, there is even a fantastic YouTube series discussing this movie in the context of instrumental rationality! And besides, I have never met anyone who did not enjoy this classic film. 

This classic film is a masterclass in group decision-making, overcoming biases, and the process of critical thinking. The plot revolves around a jury deliberating the guilt of a young man accused of murder. Initially, 11 out of the 12 jurors vote "guilty," but one juror (played by Henry Fonda) questions the certainty of the evidence. It is an absolute must-watch. 

Schindler's List: we can talk about specific rationality lessons all day, but we all know the biggest bottleneck is trying in the first place. This movie is the transformation of an ethical egoist into a utilitarian.

It also shows the value of Money: the Unit of Caring.

memento — shows a person struggling to figure out the ground truth; figuring out to whom he can defer (including different versions of himself); figuring out what his real goals are; etc.

Kinda a stretch, but Groundhog Day is about someone becoming stronger. Also just a great film.

Epistemic status: half joking, but also half serious.
Warning: I totally wrote this.

Practical Rationality in John Carpenter’s The Thing: A Case Study

John Carpenter's The Thing (1982) is a masterclass in practical rationality, a cornerstone of effective decision-making under uncertainty—a concept deeply valued by the LessWrong community. The film’s narrative hinges on a group of Antarctic researchers encountering a shape-shifting alien capable of perfectly imitating its hosts, forcing them to confront dire stakes with limited information. Their survival depends on their ability to reason under pressure, assess probabilities, and mitigate catastrophic risks, making the movie a compelling example of applied rationality.

Key Lessons in Practical Rationality:

1. Updating Beliefs with New Evidence The researchers continually revise their understanding of the alien's capabilities as they gather evidence. For instance, after witnessing the creature’s ability to assimilate and mimic hosts, they abandon naive assumptions of safety and recalibrate their strategies to account for this new information. This aligns with Bayesian reasoning: beliefs must be updated in light of new data to avoid catastrophic errors.
2. Decision-Making Under Uncertainty The characters face extreme uncertainty: anyone could be the alien, and any wrong move could result in annihilation. The iconic blood test scene exemplifies this. The test, devised by MacReady, is an ingenious use of falsifiability—leveraging empirical experimentation to distinguish humans from the alien. It demonstrates how rational agents use creativity and empirical tests to reduce uncertainty.
3. Coordination in Adversarial Environments Cooperation becomes both vital and precarious when trust erodes. The film explores how rational agents can attempt to align incentives despite an adversarial context. MacReady takes control of the group by establishing credible threats to enforce compliance (e.g., wielding a flamethrower) while demonstrating his willingness to follow the same rules he imposes.
4. Mitigating Existential Risk The characters recognize that the alien represents an existential risk—not just to them, but to humanity. Their decisions prioritize long-term outcomes over immediate survival. For example, the decision to destroy the base to prevent the alien’s escape reflects a commitment to the global utility function, even at the cost of personal survival.
5. The Role of Psychological Factors in Rationality The film does not shy away from the psychological toll of high-stakes reasoning under uncertainty. Fear, paranoia, and isolation challenge the researchers’ ability to think clearly. This resonates with real-world rationality, where emotional regulation is essential to avoid biases and maintain clarity in decision-making.

Children of Men (2006) comes to mind: a movie about a small group of people in a dying world who have the means to benefit humanity and provide hope for the future but can't agree on next steps. (The story is more nuanced but these bits seem relevant to rationality).

My first exposure to rationalists was a Rationally Speaking episode where Julia recommended the movie Locke. 

It's about a man pursuing difficult goals under emotional stress using few tools. For me it was a great way to be introduced to rationalism because it showed how a ~rational actor could look very different from a straw Vulcan.

It's also a great movie.

PT Barnum (1999)

This is a made for TV movie that can easily be found for free on YouTube.

I like it because it tells a somewhat fictionalized account of PT Barnum's life that shows him as an expert in understanding the psychology of people and figuring out how to give them products they'll love. Some might say what he does is exploitative, but the movie presents him as not much different than modern social media algorithms that give us exactly what we want, even if we regret it in hindsight.

The rationalist angle is coming away with a sense of what's it's like to be a live player who is focused on achieving something and in deep contact with reality to achieve it, willing to ignore social scripts in order to get there.

Total Recall (1990)

Based on the Phillip K. Dick short story "We Can Remember It For You Wholesale". The movie is better than the short story.

I can't tell you why this is a rationality movie without spoilers...

Doubt: late answer because I just watched this two days ago, but I found it a fantastic exploration of the problem of reasoning and making decisions with incomplete information and very high stakes. Part of the point being that the viewer does not get a privileged outlook and shares information with the PoV characters, meaning the movie makes you experience the problem deeply.

The two Gurren Lagann movies cover all the events in the series, and based on my recollection, they should be better animated. Still based on what I remember, the first should have a pretty central take on scientific discovery. The second should be more about ambition and progress, but both probably have at least a bit of both. It's not by chance that some e/accs have profile pictures inspired by that anime. I feel like people here might disagree with part of the message, but I think it does say something about issues we care about here pretty forcefully. (Also, it was cited somewhere in HP: MoR, but for humor.)

Tenet (2020) by George Nolan revolves around recursive thinking and responding to unreasonably difficult problems. Nolan introduces the time-reversed material as the core dynamic, then iteratively increases the complexity from there, in ways specifically designed to ensure that as much of the audience as possible picks up as much recursive thinking as possible.

This chart describes the movement of all key characters plot elements through the film; it is actually very easy to follow for most people. But you can also print out a bunch of copies and hand them out before the film (it isn't a spoiler so long as you don't look closely at the key).

Most of the value comes from Eat the Instructions-style mentality, as both the characters and the viewer pick up on unconventional methods to exploit the time reversing technology, only to be shown even more sophisticated strategies and are walked through how they work and their full implications.

It also ties into scope sensitivity, but it focuses deeply on the angles of interfacing with other agents and their knowledge, and responding dynamically to mistakes and failures (though not anticipating them), rather than simply orienting yourself to mandatory number crunching.

The film touches on cooperation and cooperation failures under anomalous circumstances, particularly the circumstances introduced by the time reversing technology.

The most interesting of these was also the easiest to miss:

Quest (1984)

This movie was written by Ray Bradbury.

It's about people who have 8 day lifespans, and follows the story of a boy who grows up to fulfill a great quest. I like it from a rationalist standpoint because it has themes similar to those we have around AI, life extension, and more: we have a limited to achieve something, and if we don't pull it off we are at least personally doomed, and maybe societally, too.

ThingOfThings said that Story of Louis Pasteur is a very EA movie, but I think it also counts for rationality. Huge fan.

Cast Away (2000) is a great study of an (otherwise average) man using the absolute height of his rationality to survive on a deserted island. Unlike the Martian, or many similar examples, the protagonist of Cast Away is NOT a scientist, nor a person with he kind of education and training to focus their rationality (well, he seems to be a logistics manager so his mental skills must be at least weakly adjacent to optimization, but not much). His survival depends not on some pre-thought mental models, but on applying raw, simple clear thinking to entirely unfamiliar problems.
The movie shows the processes of his survival struggles in loving detail, including his failures, insights and progress.
Importantly, it also shows what happens when a person who had spent years fighting for survival by using their intelligence to solve purely technical problems is at a loss when trying to apply the same kind of rational reasoning to human affairs, which are rife with compounded irrationality (a problem a lot of Rationalists can empathize with).

Riders of Justice:    imdb.com/title/tt11655202/

Recognizing patterns in a mainly random world, psycho-therapeutic hacking strategies. Can't say much more without risking spoilers. 

"The Prime Gig": explores the life of Pendleton "Penny" Wise, a charismatic but morally conflicted telemarketer, as he navigates the cutthroat world of high-stakes sales schemes. Torn between ambition, romance, and integrity, he must decide whether to pursue wealth at the cost of his principles.

https://m.imdb.com/video/embed/vi4227907353/