Chicago Rationality

Welcome to the homepage for the Chicago Rationality meet-up group! 

Our group includes people interested in Rationality, Effective Altruism, and more. Many people find us through weird corners of the internet like LessWrong, Slate Star Codex/Astral Codex Ten, Overcoming Bias, Marginal Revolution, and other Rationalist-adjacent sites.

If you’re interested in hanging out in real life with other people interested in these kinds of ideas, attend our next meet-up! We typically do one “discussion” meet-up per month focused on a specific reading suggested by a group member and one “social” meet-up per month with no particular agenda.

You can learn more about our meetups here.

It’s ok to come if you’re not sure if you’ll fit in, if you’re not the “typical” kind of person who would attend a meet-up like this, or if you’re just kind of intimidated by coming to a new social event. 

Feel free to reach out to us with any questions as well:

If you’d like to be notified of upcoming meet-ups and social events, please fill out the form below and you’ll be added to our mailing list. We usually send out emails a few times per month.


Click through on the event description for more details including address, suggested reading, etc.

You can also add this calendar to your calendar of choice


December 2019 Meetup: Arrow’s Impossibility Theorem

Thanks Noah for suggesting the following readings & podcast! 1. 2. 3. 4.

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November 2019 Meetup: Going Critical – Phase Transitions in Social Behavior

1. On critical thresholds and cultural/scientific diffusion: 2. A second reference on critical thresholds (sorry for the self-reference but I’m rushing): 3. Look up the definition of “phase transition” [possible cool topic for future meeting—things that hover near criticality..]

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September 2019 Meetup: Free Will

Hey all—by some kind of emergent process, we have self-organized a topic for next meetup: Free Will. This is a VAST topic with a ton of writings. Any recommendations? Here are a few possibilities, H/T Shane with an addition by myself: a) Rationalist: Yukdowski (I’d grab the last few posts):

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August 2019 Meetup: Field Trip: Depolarizing the Politics Within

1. A Human’s Guide to Words: What are words, how are they useful, how can they be wrong, how can we avoid being wrong? Drawn from this sequence: 2. Inside/outside views : People are oftentimes bad at estimation. This can oftentimes be improved by reference class forecasting (“Outside view”).

Read More »


If you’re considering coming to a meetup but would like some more info on how things work, you’re in the right place!

Our monthly discussion meetups typically have some suggested readings, videos, etc. — these could be blog articles, academic journals, lectures, or podcasts. We typically meet for about 2.5 hours and discuss the topics from the readings. You can check out past meetup topics here.

Meetup attendance is typically in the range of 10-30 people. Depending on how many people we have, we usually start with a brief group discussion laying out the main ideas from the readings, then we split into smaller groups to facilitate better conversations.

You are by no means required to do all (or honestly even any) of the reading ahead of time. Typically about 1/3 of people do all of the reading, 1/3 do some of the reading, and 1/3 do barely any of the reading. You are also not required to actually participate in the discussion! We love to hear what everyone thinks, but you’re welcome to attend and just listen.

Our social meetups are much more ad hoc. We’ve hosted social meetups at apartments, parks, and restaurants — people typically just hang out and chat.

We also post in our Discord. Feel free to join even if you’re not local to Chicago. If you’re not familiar with Discord, it’s a social instant messaging app similar to Slack or, for the old heads, IRC. Here’s a Beginner’s Guide to Discord. We share articles and memes, organize game nights and hiking trips, and share other rationality-adjacent events on the Discord.

If you’re curious about our meetups and have questions, please feel free to reach out at

Internet Nerds go outside, too
Chicago Rationality — est. 1900



Shane became interested in rationality by way of blogs, like so many, particularly Slate Star Codex (SSC). At his first SSC meetup in 2018, he joined an email list to revive the then dormant Chicago Rationality group, and he’s been active with Chicago Rationality ever since. When he’s not attending meetups, Shane is a professor of Linguistics and Spanish at University of Illinois Chicago, with a particular interest in bilingualism and syntactic theory.


Todd is a longtime reader of nerdy corners of the internet and started attending Chicago Rationality meetups in 2019. After the group grew large enough to get kicked out of library meeting rooms, Todd offered to host meetups in the mezzanine space at his CrossFit gym, South Loop Strength & Conditioning. Todd is also a data scientist at the University of Chicago’s Data Science Institute with an interest in both applying machine learning to hard science and social impact work as well as theoretical machine learning.


Chicago Rationality strives to host welcoming and safe meetups.

Let’s be real: lots of weirdos come to Rationality meetups. Many of us have, uh, non-standard social skills. This is good! There are, however, some behaviors that create problems for the group as a whole that we want to avoid.

Rule #1: Be civil and assume good faith. Avoid personal attacks. If someone disengages from an argument, leave them alone. Don’t be someone who causes more drama than your contributions are worth.

Rule #2: No sexual harassment. All members of the Chicago Rationality community should be able to participate free from sexual harassment.

Rule #3: Be careful with “culture war” discussions. The Rationality community prides itself on discussing sensitive topics with nuance, but that doesn’t mean that everyone wants to talk about culture war. In fact, many people actively do not want to talk about culture war topics! If you’re not sure if it’s culture war, it’s probably culture war.

Rule #4: Contribute to the discussion (if you like), but allow others to speak. Not all of your thoughts need to be fully organized in order to contribute, but be cautious of rambling or talking over other participants. It’s better to end your thoughts too early than too late!

Enforcement: Enforcement will be at the organizers’ discretion. Usually, we will give specific feedback on a behavior that is causing issues. If you keep doing it, you may be asked not to attend in-person meetups. If your behavior is “way over the line,” we will ban you immediately.

If you’d like to report something, please email us at

Links and REsources

Looking for more internet to read? Curious about what Rationality groups talk about? Want to go go to other meetups in Chicago? Here are some helpful links: