New preprint! w/Tessa Charlesworth & @williambrady.bsky.social: The Psychology of Algorithmic Bias We introduce a psychology-centered framework to specify mechanisms through which human behavior interacts dynamically with AI systems to produce algorithmic bias. osf.io/preprints/psyarxiv/rxu37_v1

New preprint! ✨ Do you and your partner have made-up words ("eggy" to mean awkward)? Do you and your bestie have an anecdote you love to tell together (that time one of you tripped over an acorn)? Do you and your closest colleague have a cherished ritual (weekly lunch at "the usual spot")? 🧵

They double-booked a room for the "Healthy, Wise, Wealthy, Decision Making" and "Moral Machines" sessions at SPSP, but @williambrady.bsky.social exercised some masterful (& healthy & wise & moral & wealthy?) negotiation skills and we're now getting two sessions of talks in one 😊

@killianmcloughlin.bsky.social social media news especially likely to use villian / victim framing; low quality news especially; more likely to evoke outrage and draw engagement when doing so #spsp

New work from @drsanaz.bsky.social : using smart phone sensing data, one of the biggest predictors of people higher on authoritarian measure was Facebook and social media use #spsp

Many think LLM-simulated participants can transform behavioral science. But there's been a lack of accessible discussion of what it means to validate LLMs for behavioral scientists. Under what conditions can we trust LLMs to learn about human parameters? Our paper maps the validation landscape. 1/

We're excited about the upcoming Computational Psychology preconference at @spspnews.bsky.social this Thursday. See our action-packed full day agenda below! Featuring 3 keynote talk themes with related early-career speakers, data blitz session, panel discussion. Don't miss it! #SPSP

Last year at SPSP we had some great discussions about research with LLMs. This time #spsp2026 we're back with a whole workshop! Friday 2/27 at 8am, + informal drinks at 6pm to continue the conversation More info, plus a chance to submit discussion topics, here: spsp2026.carrd.co

Interested in why moral conflict is so common on social media? Join us at #SPSP 2026 for our symposium. We’ll present new findings on how platforms shape digital discourse and explore pathways toward healthier online environments 🗓 Saturday, the 28th | 9:30–10:40 AM 📍 Room E270, Level 2

Very honored by this one! Thanks to all my mentors, students and colleagues who made it possible! And congrats to all the recipients for their amazing work.

For folks interested in learning about our lab's research, check out this flier with all our presentations at this coming #SPSP2026 conference @spspnews.bsky.social. With research by several rising stars covering tech, culture, politics and more Credit to our talented lab manager Hanying Yao!

Congrats to @mjcrockett.bsky.social on the Troland Research Award from @nasonline.org ! Having witnessed the "unusual achievement" first hand, very happy to see the recognition 🌹💐 www.nasonline.org/award/trolan...

Before the end of this year, I’m glad to share a short perspective/policy piece, recently out with @joshcjackson.bsky.social , Zhao Wang, and @williambrady.bsky.social: “Large AI Models Have a Prioritization Problem: Policy Implications and Solutions.”

New preprint: Empathy, Thick and Thin papers.ssrn.com/sol3/papers.... It is perhaps foolhardy to attempt to say something new about a topic as widely studied as empathy. I tried anyway! 1/

New from me - how AI-generated political videos have become just another part of social media, used to entertain, outrage and monitize attention theconversation.com/ai-generated...

Out now in Scientific Reports! Despite high correlations, ChatGPT models failed to replicate human moral judgments. We propose tests beyond correlation to compare LLM data and human data. With @mattgrizz.bsky.social @andyluttrell.bsky.social @chasmonge.bsky.social www.nature.com/articles/s41...

So there you have it, twin study estimates were greatly inflated, and molecular data sets the record straight. I walk through possible counter-arguments, but ultimately the uncomfortable truth is that genes contribute to traits much less than we always thought.

Great work by @natematias.bsky.social & Megan Price: public involvement in AI is an important part of rigorous science. AI systems are sociotechnical, meaning that the lived experience of the public is essential for validation, etc. www.pnas.org/doi/10.1073/...

New preprint out 📄 “Why Reform Stalls: Justifications of Force Are Linked to Lower Outrage and Reform Support.” Why do some cases of police violence spark reform while others fade? We look at how people explain them—through justification or outrage. osf.io/preprints/ps...

🚨Out in PNAS🚨 Examining news on 7 platforms: 1)Right-leaning platforms=lower quality news 2)Echo-platforms: Right-leaning news gets more engagement on right-leaning platforms, vice-versa for left-leaning 3)Low-quality news gets more engagement EVERYWHERE - even BlueSky! www.pnas.org/doi/10.1073/...

Excited to share a new preprint, accepted as a spotlight at #NeurIPS2025! Humans are imperfect decision-makers, and autonomous systems should understand how we deviate from idealized rationality Our paper aims to address this! 👀🧠✨ arxiv.org/abs/2510.25951 a 🧵⤵️

✨New preprint! Why do people express outrage online? In 4 studies we develop a taxonomy of online outrage motives, test what motives people report, what they infer for in- vs. out-partisans, and how motive inferences shape downstream intergroup consequences. Led by @felix-chenwei.bsky.social 🧵👇

These has been sharp rise in moralized language on social media Two processes explained this shift: (1) within-user increases in moral language over time (2) highly moralized users became more active while less moralized users disengaged osf.io/preprints/ps...

Posting is correlated with affective polarization: 😡 The most partisan users — those who love their party and despise the other — are more likely to post about politics 🥊 The result? A loud angry minority dominates online politics, which itself can drive polarization (see doi.org/10.1073/pnas...)

Reminder to apply to the DRRC postdoc fellowship! Deadline is this week.

Re-posting this because I really like it and I think we need to understand identity from a functionalist perspective more than ever. osf.io/preprints/ps...

1. We ( @jbakcoleman.bsky.social, @cailinmeister.bsky.social, @jevinwest.bsky.social, and I) have a new preprint up on the arXiv. There we explore how social media companies and other online information technology firms are able to manipulate scientific research about the effects of their products.

Great piece on the absurdity of brute force multiverse analyses. www.pnas.org/doi/10.1073/...

Can AI simulations of human research participants advance cognitive science? In @cp-trendscognsci.bsky.social, @lmesseri.bsky.social & I analyze this vision. We show how “AI Surrogates” entrench practices that limit the generalizability of cognitive science while aspiring to do the opposite. 1/

Last call for data-blitz and poster submission for the Computational Psychology preconference @spspnews.bsky.social! See thread below for details and hope to see you in Chicago!

🚨 New preprint 🚨 Across 3 experiments (n = 3,285), we found that interacting with sycophantic (or overly agreeable) AI chatbots entrenched attitudes and led to inflated self-perceptions. Yet, people preferred sycophantic chatbots and viewed them as unbiased! osf.io/preprints/ps... Thread 🧵

Our new paper finds that AI can overcome partisan #bias We find that AI sources are preferred over ingroup and outgroup sources--even when people know both are equally accurate (N = 1,600+): osf.io/preprints/ps...

The computational psych preconference is back @spspnews.bsky.social for a full day! This year's lineup: 👉theory-driven modeling: Hyowon Gweon 👉data-driven discovery: @clemensstachl.bsky.social 👉application: me 👉 panel: @steveread.bsky.social Sandra Matz, @markthornton.bsky.social Wil Cunningham

Only a small % of people engage in toxic activity online, but they’re responsible for a disproportionate share of hostile or misleading content on nearly every platform Because super-users are so active, they dominate our collective impression of the internet www.theguardian.com/books/2025/j...

New dataset that describes social media activity of a very large group of US elected officials: www.nature.com/articles/s41...

And here we are

Really cool work led by @hongkai1.bsky.social ✨ observational and experimental studies finding that differentiation helps explain the evolution of negative discourse online!

@aoc.bsky.social come hang out at Northwestern and we'll take you surfing on the great lakes!

I have been taking surfing lessons. Still in the beginner kook trenches, but celebrating my last time on a foam board 😎 Graduating to a hard top next session. It’s fun to learn new things! Even if you look like a goober at the beginning. 🏄🏽‍♀️

Yet again, machine learning — even gussied up via the transformer architecture — encodes and reinforces societal biases. This study reveals that LLM-based peer review relies heavily on author institution in its decisions. arxiv.org/abs/2509.15122

I suspect we are already at the point where students view writing a dissertation without LLMs the same as us millennials viewed writing a dissertation on a typewriter, i.e., unfathomable. No value judgment, just interesting how quickly that escalated.

Attempts at reducing online aggression (ie, cruel Reddit comments) by increasing empathy (eg, "There is a human being on the other side who might be hurt by your words") tended to backfire. www.sciencedirect.com/science/arti...

"psychological biases to overestimate the influence of self-interest on others’ behaviors and to attribute malicious intentions to those who harm us may create inherent challenges for punishment to effectively promote cooperation"

Apply to the awesome DRRC postdoc position at Kellogg. Open to any scholar who studies conflict and cooperation, very broadly construed. We’ve had some amazing people come through over the years. Note the earlier application deadline this year (Nov 1)!

📢JOB POSTING: Senior Director for the Center for Enlightened Disagreement (CED).📢 @nourkteily.bsky.social and I seek a strategic leader to help us build the Center (see ensuing post for information about CED). Target salary range: $125,000-$155,000. 1/2 careers.northwestern.edu/psc/hrnu_er/...

Check out our new pre-print in which we argue something that might be obvious but doesn't seem to be obvious to everyone: Large Language Models (such as ChatGPT) do not simulate human psychology.

Are you interested in topics related to conflict and intergroup relations *broadly construed*? Come join us as a postdoc in the Dispute Research Research Center! This position is up to 3 years, comes with your own research funding, and a phenomenal network of past DRRC postdocs.

🔖 NEW PAPER ALERT 🔖 Out in PNAS – we used equation discovery algorithms to improve models of human reinforcement learning. Led by the wonderful Kyle Lafollette with an amazing team Yanni Yuval @roeyschurr.bsky.social and @d-melnikoff.bsky.social www.pnas.org/doi/epdf/10....

Had a great time teaching a CSS workshop at SISPP - thanks to all the students and organizers! Future of social psych is looking bright 😎

If you're at @aomconnect.bsky.social #AOM2025, come check out our panel on NLP in organizations, featuring @dholtz.bsky.social, Sameer Srivastava, @williambrady.bsky.social, @mikeyeomans.bsky.social & me! We'll explore topics including hiring, cooperation, agency, and moral outrage -- don't miss it!