Paul E. Smaldino | Lightnews

Paul Smaldino

@psmaldino.bsky.social

5.8K followers 940 following 720 posts

Paradigmatically promiscuous scientist. Ankylosaur enthusiast. Modeler of cultural evolution and related topics. Anti-fascist. Professor at UC Merced and the Santa Fe Institute.
Web: https://smaldino.com/wp/

Videos

Physics 20%

Sociology 17%

Posts Replies Media Videos

The New York Times @nytimes.com · 16h

Breaking News: The EPA will stop considering lives saved when setting pollution limits and instead calculate only the cost to businesses.

E.P.A. to Stop Considering Lives Saved by Limiting Air Pollution

In a reversal, the agency plans to calculate only the cost to industry when setting pollution limits, and not the monetary value of saving human lives, documents show.

nyti.ms

Reposted by Paul E. Smaldino

Mike Makowsky @mikemakowsky.bsky.social · 19h

Pluribus is a fascinating meditation on an extreme solution to the crux of all political economy: what's the best way to facilitaton cooperation among strangers? Anyway, here's a book I was going to write collapsed to 2500 words.
economistwritingeveryday.com/2026/01/12/t...

The Cooperative Corridor

The confluence of politics, recent interest in agent-based computational modeling, and Pluribus have convinced me now is the time to write about the “Cooperative Corridor”. At one point…

economistwritingeveryday.com

Reposted by Paul E. Smaldino

McSweeney's @mcsweeneys.net · 2d

Sadly, more relevant than ever. www.mcsweeneys.net/articles/im-...

I’m a German Citizen in 1933, and Is It Just Me or Is It Really Hard to Get Any Work Done Right Now?

Our 25th most-read article of 2025. - - -Guten tag. I’m just wondering if anybody else can relate to this feeling I’ve been having that I just can...

www.mcsweeneys.net

Paul Smaldino @psmaldino.bsky.social · 3d

The source of much online outrage, distilled in a pithy figure.

Jerry Chen @jcsalterego.bsky.social · 3d

a diagram of a funnel with "your post" at the top. through the funnel there are several cross-sections:

- audience: you, comprehension of your post: 100%
- audience: followers, comprehension of your post: 90%
- audience: followers of followers, comprehension of your post: 50%
- audience: followers of followers of followers, comprehension of your post: 20%

through the bottom of the funnel are "replies to your post" with several posts with stinky lines

Paul Smaldino @psmaldino.bsky.social · 3d

Good news! m.youtube.com/shorts/tqOkW...

"An escalator can never break..." 🎤: Mitch Hedberg #shorts

YouTube video by Comedy Central Stand-Up

m.youtube.com

Reposted by Paul E. Smaldino

Faine Greenwood @faineg.bsky.social · 6d

little-flying-robots.ghost.io/rejecting-re...

We live in an age where the Internet and LLMs are encouraging ever more people to reject reality entirely.

Here's my thoughts on why this is happening, and why the Terminally Online turn amongst the powerful is so dangerous.

Rejecting Reality in the Age of AI

The Internet and AI are encouraging more and more people to deny reality itself. Here's why that's bad.

little-flying-robots.ghost.io

Paul Smaldino @psmaldino.bsky.social · 6d

I find the neo-royalism framing useful and I think @abenewman.bsky.social is probably right with this interpretation

Abe Newman @abenewman.bsky.social · 7d

1/Leaders are abducted/allies are threatened but pundits and governments are scratching their heads on what the US is doing. Danish PM on Greenland "It makes absolutely no sense". Why? Because actors using old IR models when we need a new lens. Enter neo-royalism.
abcnews.go.com/Internationa...

Denmark's PM urges Trump to 'stop the threats' of annexing Greenland

The prime minister of Denmark called on Trump to “stop the threats” of the U.S. annexing Greenland after renewed comments garnered international attention.

abcnews.go.com

Abe Newman @abenewman.bsky.social · 7d

Denmark's PM urges Trump to 'stop the threats' of annexing Greenland

The prime minister of Denmark called on Trump to “stop the threats” of the U.S. annexing Greenland after renewed comments garnered international attention.

abcnews.go.com

Paul Smaldino @psmaldino.bsky.social · 10d

Here's a PDF to save you time. smaldino.com/wp/wp-conten...

smaldino.com

Paul Smaldino @psmaldino.bsky.social · 10d

I think you'll enjoy the paper. We specifically look at that (they do, but only if they have very large wealth buffer).

Paul Smaldino @psmaldino.bsky.social · 10d

Thanks Brad, would love to hear your thoughts. It does make risk preferences endogenous! They emerge through (both individual and social) learning, and the traits that evolve are the strategies for learning about risk.

Paul Smaldino @psmaldino.bsky.social · 10d

Personal risk tolerance has sweeping implications for how societies evolve.
phys.org/news/2025-12...

Personal risk tolerance has sweeping implications for how societies evolve

In his biography of Elon Musk, historian Walter Isaacson describes a game of Texas Hold "Em poker in which Musk went all in—on every hand.

phys.org

Paul Smaldino @psmaldino.bsky.social · 11d

Wikipedia is truly one of the greatest things on the Internet. It is absolutely incredible, and must be preserved at all costs.

Reposted by Joanna Bryson, Paul E. Smaldino

Rebecca Tushnet @rtushnet.bsky.social · 12d

Oh look, a machine for false advertising designed to defeat any class treatment even without arbitration clauses!

Matt Seybold @mattseybold.bsky.social · 13d

what a shocking turn of events
who could’ve seen this coming

OpenAI Reportedly Planning to Make ChatGPT "Prioritize" Advertisers in Conversation

OpenAI employees working on ChatGPT report plans to unleash sponsored advertisements above organic results.

futurism.com

Reposted by Christian Odendahl, Rosemary A. Joyce, Paul E. Smaldino , and 2 more Christian Odendahl, Rosemary A. Joyce, Paul E. Smaldino, Trevor A. Branch, Greg Linden

Michael Li (李之樸) @mcpli.bsky.social · 12d

The final Calvin and Hobbes, which appeared in papers 30 years ago today.

Paul Smaldino @psmaldino.bsky.social · 13d

I use this psa in lectures all the time despite the students not having any idea what I’m referencing.

Paul Smaldino @psmaldino.bsky.social · 13d

I will (over)use em-dashes till they pry them from my cold dead hands.

Dr Lindsey Fitzharris @drlindseyfitz.bsky.social · 13d

OMG - f*ck AI for ruining the em-dash for writers. I use them all the time. Of course, what a shock that AI uses them since they were trained off my voice and other authors' voices.

Jen Zingsheim Phillips @jenzings.bsky.social · 13d

I'm a writer who has specifically been directed *not* to use em-dashes because "they mean it was written by AI." I can detect AI writing, but it is not simply a matter of the punctuation used.

Reposted by Lesley A. Hall, Paul E. Smaldino, Michael H. Whitworth , and 1 more Lesley A. Hall, Paul E. Smaldino, Michael H. Whitworth, Alex Drace‐Francis

Dr Lindsey Fitzharris @drlindseyfitz.bsky.social · 13d

OMG - f*ck AI for ruining the em-dash for writers. I use them all the time. Of course, what a shock that AI uses them since they were trained off my voice and other authors' voices.

Jen Zingsheim Phillips @jenzings.bsky.social · 13d

I'm a writer who has specifically been directed *not* to use em-dashes because "they mean it was written by AI." I can detect AI writing, but it is not simply a matter of the punctuation used.

Paul Smaldino @psmaldino.bsky.social · 13d

IMO rational actor models suffer more from this critique. Evolutionary models can allow for the overall optimal out of bounded rational agents and even produce individual differences via frequency dependence. That said, there’s usually more variation in real life than in models, so caution is good.

Paul Smaldino @psmaldino.bsky.social · 14d

"Why agent-based modeling could happen in economics. Eventually." Good piece by @mikemakowsky.bsky.social
economistwritingeveryday.com/2025/12/29/p...

I'd argue that the "new era of theory" is already underway, though, led not by economists, but by comp social sci/cultural evolution folks.

Part II: Why agent-based modeling could happen in economics. Eventually.

Three years ago I ruminated on why agent-based modeling never got any real traction in economics. It got a suprising amount of attention and I continue to receive emails about it to this day. I too…

economistwritingeveryday.com

Paul Smaldino @psmaldino.bsky.social · 17d

Merry Christmas!

Paul Smaldino @psmaldino.bsky.social · 17d

TBF, it’s mentioned only very briefly to discuss Dust and how elementary particles are be detected. We stopped and had a chat because I wanted to highlight that while Dust was fictional, particles and radiometers weren’t. She lit up when I told her the CR was real and asked for one.

Paul Smaldino @psmaldino.bsky.social · 17d

After learning of their existence from His Dark Materials, my 11 yr-old daughter asked for a Crookes Radiometer for Xmas. I now regret every moment in which I didn’t have one in the house.

Reposted by Paul E. Smaldino

Thomas Shahan @tshahan.bsky.social · 21d

my modest collection of flies with WIDE heads 🙇

a hammer-headed Richardia (Ecuador),
a stalk-eyed Chaetodiopsis (Mozambique),
a pointy-eyed Ophthalmoptera (Colombia),
and an antlered Richardia (Colombia)

why though? male-male competition? sexual selection? chime-in if you know!

Reposted by Paul E. Smaldino

McSweeney's @mcsweeneys.net · 22d

"It would be easy for me to dismiss my ignorance as a result of my youth. I was only 16 going on 17 when the relationship in question occurred, and up until that point, the men in my life —namely my father and significant others — insisted on infantilizing me."

I Am Liesl von Trapp and I Owe the Resistance an Apology

A few months ago, I was caught on camera during an intimate moment with a male companion in my family’s gazebo. At the time, my primary concern was...

buff.ly

Reposted by Paul E. Smaldino

Ben Allen @evodynamics.bsky.social · 26d

TIL that 3-6% of birds across five species have morphological sex characteristics that differ from their chromosomes.

royalsocietypublishing.org/rsbl/article...

Prevalence and implications of sex reversal in free-living birds

Abstract. The ability to unequivocally identify the sex and reproductive status of individuals is crucial across many fields of study. Recent evidence indi

royalsocietypublishing.org

Reposted by Paul E. Smaldino

Alejandro Pérez Velilla @apvelilla.bsky.social · 27d

New preprint out with @elspethready.bsky.social : "The emergence of sharing networks through indirect signaling".

osf.io/preprints/so...

OSF

osf.io

Paul Smaldino @psmaldino.bsky.social · 28d

Woke up this morning to 6 new review requests. It’s a Christmas miracle.

Paul Smaldino @psmaldino.bsky.social · Dec 11

We are very close to releasing a new code repo in Julia for all the models in Modeling Social Behavior! Stay tuned.

Reposted by Nicholas A. Christakis, Rebecca Sear, David W. Lawson

Paul Smaldino @psmaldino.bsky.social · Dec 9

Super proud of this paper with @apvelilla.bsky.social and @babeheim.bsky.social, now out in Psych Review.

Non-paywalled version (preprint) here: osf.io/preprints/so...

Santa Fe Institute @sfiscience.bsky.social · Dec 9

How likely are you to invest in a new business? Ask your partner to marry you? Move to a new country?

A new model by SFI External Professor Paul Smaldino and colleagues explains how wealth, experience, and environment shape our risk tolerance — and how those effects persist across generations.

Personal risk tolerance has sweeping implications for how societies evolve

How much risk is any individual willing to take on? That depends, in part, on their individual resources and environment, which shape the learning strategies that influence their personal proclivity t...

Add to Home Screen

Light up
your news

Add to Home Screen

Light upyour news

Sign in to Lightnews

Sign up to start reading

Connect Bluesky

Connect with Bluesky

Light up
your news