Alejandro Pérez Velilla

Individual social identities indicate group affiliations and are typically associated with 3 group-typical preferences, signals that indicate group membership, and the propensity to condition actions on the social signals of others, resulting in group-differentiated interaction norms. Past work modeling identity signaling and coordination has typically assumed that individuals belong to one of a discrete set of groups. Yet individuals can simultaneously belong to multiple groups, which may be nested within larger groupings. Here, we introduce the generalized Bach or Stravinsky game, a coordination game with ordered preferences, which allows us to construct a model that captures the overlapping and hierarchical nature of social identity. Our model unifies several prior results into a single framework, including results related to coordination, minority disadvantage, and cross-cultural competence. Our model also allows agents to express complex social identities through multidimensional signaling, which we use to explore a variety of complex group structures. Our consideration of intersectional identities exposes flaws in naive measures of group structure, illustrating how empirical studies may overlook some social identities if they do not consider the behaviors that those identities function to afford.

New preprint w/ Nathan Gabriel & @avbell.bsky.social: The Evolution of Identity Signals for Coordination in Diverse Societies

The model tackles multiple nested/overlapping identities and complex signaling structure. Recovers lots of old results and adds several new ones osf.io/preprints/so...

Job announcement 🚨: paid fieldwork opportunity with Sanguatsiniq research project! Details in thread ⬇️ Please share!

Author-Paid PublicationFees Corrupt Science and Should Be Abandoned Thomas J. H Morgan & Paul E. Smaldino

As grant money starts drying up, it's more important than ever not to waste it on paying publishers' open access "article processing fees" when we can host PDFs for free. Tom Morgan and I wrote a paper on this, forthcoming at Science and Public Policy. Accepted draft here: osf.io/preprints/os...

Here's the stable link to the most recent version 👀

osf.io/preprints/ps...

decision trees in human play in the game of go before and after the arrival of superhuman AI, showing gradual change rather than revolutionary disruption

🚨 New preprint! 🚨

I looked at 400+ years of cumulative cultural evolution in the Game of Go from feudalism to superhuman AI. Did AlphaGo etc. completely disrupt human play? No! More like human-machine convergence, rather than revolution.

Check out these decision trees!

osf.io/preprints/ps...

Merced River, Yosemite National Park

meme with escalating multilevel priors, from fixed to simple random to correlated random effects

Complex generalized linear multilevel model with an image of a monster emerging from the ocean behind it

Week 7 of my Bayes stats course, now deep in multilevel models, correlated effects, centered and non-centered parameterizations, diag(σ)LZ ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn (link to lectures: github.com/rmcelreath/s...)

L'Impératrice

Sea Power
La máquina de hacer pájaros
El baquiné de Angelitos Negros de Willie Colón

Bird Flu Is a Big Threat. The US Needs to Start Acting Like It. Scientists suspect a new strain is spreading via dust from bird droppings, carried by the wind.

We are gutting EIS and our general capacity to respond to novel infectious threats right as bird flu is ramping up. What could possibly go wrong?

www.bloomberg.com/opinion/arti...

In game theory, we often assume that people only interact in one game at a time. In a new paper, we explore theoretically and experimentally how people cooperate when they engage in two games concurrently, either with the same partner or with different partners, www.nature.com/articles/s41...

Where do moralizing religions come from? Useless cognitive by-products?Cultural group selection for complex societies?

Our Psych Review paper argues: neither. Let’s rethink their cognitive & evolutionary origins🧵
w/ @manvir.bsky.social @nbaumard @jbaptistandre.bsky.social

doi.org/10.1037/rev0...

Looking for a first intro to theoretical models in cultural evolution? For yourself or your students? 🔍

In our chapter for an upcoming @ehbea.bsky.social textbook, we outline what models are for, what questions they address, and how they can be coded in R!

Preprint: osf.io/preprints/ps...

Postdoctoral researcher in social cognition | Masaryk University

Postdoc position available in our team!

We are testing a computational model explaining the decision-making process during in normative/moral situations while incorporating the formative role of culture in this process.

www.muni.cz/en/about-us/...

#socialpsyc
#PsychSciSky
#cogpsyc

💥Two 💥 post-doc positions open in my @erc.europa.eu ERC-funded group. In an interdisciplinary, collaborative setting, we use different types of modeling (e.g., reinforcement learning) and human experiments to understand social learning and cultural evolution. Get in touch if you have any questions!

Does poverty lead to risk taking or risk avoidance? Turns out, to both. Our new paper (with D. Nettle & W. Frankenhuis) in @royalsocietypublishing.org explains why, and conducts preregistered tests of our ‘desperation threshold’ model.

royalsocietypublishing.org/doi/10.1098/...

A 🧵

Andy Whiten and I wrote a @science.org perspective about a cool new study from @inbalarnon.bsky.social @simonkirby.bsky.social @ellengarland.bsky.social et al! They found humpback whale song has language-like statistical structure, using methods inspired by infant language learning 🐋🎶 Links below ⬇️

We're hiring! Are you a cultural evolutionary modeller who wants to understand how and why children's peer cultures evolve? Here's a postdoc position for you! @culturalevolsoc.bsky.social @durhampsych.bsky.social @ehbea.bsky.social @eslr.bsky.social

Apply here: durham.taleo.net/careersectio...

Cultural evolution in song of Geothlypis philadelphia (Mourning Warbler) - American Ornithological Society We used a long-term database of songs recorded over 36 years from throughout the breeding range of Geothlypis philadelphia (Mourning Warbler) to answer questions about the current and historical patte...

Lovely blog post about our recent paper in Ornithology (@amornith.bsky.social)! We applied agent-based models and machine learning to 36 yrs of mourning warbler song, and found evidence that males have a learning bias for more complex syllables: americanornithology.org/cultural-evo...

Language-like efficiency in whale communication Whale vocalizations follow efficiency rules seen in human language, revealing striking similarities in communication systems.

Do whales optimize their vocalizations for efficiency, just like human language? 🐋🎶 My latest study in
Science Advances (@science.org) suggests they do—following linguistic laws seen in human speech. 🧵 www.science.org/doi/10.1126/...

a schematic depiction of a trend line and several causal forces that give it its shape

Change over time is often depicted as a trendline. But what does shape a trendline? Which forces? Our new paper presents a method allowing to “decompose” trendlines into constituent forces. Also, we tackle an old puzzle: Does culture change “one funeral at a time”? 🧵(1/8) doi.org/10.1098/rspb...

🏰 PhD position on computational modelling | collective dynamics | cultural evolution 🏰

Get in touch with any questions you might have and join me in beautiful Marburg!

stellenangebote.uni-marburg.de/jobposting/c... (Deutsch)

stellenangebote.uni-marburg.de/jobposting/3... (English)

Perceived inequality and variability in the expression of parochial altruism | Evolutionary Human Sciences | Cambridge Core Perceived inequality and variability in the expression of parochial altruism - Volume 7

"It's us vs them." Is it always? …and if it isn’t, when might it be them = us, or even them > us?? In a new paper, Cody Ross and I find that perceived cooperativeness and need can flip the equation. Here’s a thread 👇🏻 and here’s the paper: doi.org/10.1017/ehs.... /1

Good words to remember when things are falling apart...

Alt-librarians, alt-IT?

This is definitely the best way to thank them.

archive.org/donate

They are never flush with enough money to thrive.

The newly established research group Computational Modelling of Behaviour is seeking applicants for a PhD position in one of the following research areas: Collective dynamics and cultural evolution, social decision-making, cognitive modeling, Bayesian statistics, causal inference, cross-cultural methods. Tasks: conducting independent research in the group's areas of interest, e. g., interactive group experiments on social dynamics, cognitive or agent-based modeling, analysis of panel data or large cultural datasets, field research, cross-cultural studies scientific services in research and teaching contributing to the group’s research agenda and contributing to third-party funding applications publishing results at scientific conferences and in journals

My former PhD @dominikdeffner.bsky.social is now a professor and is looking for a PhD student. Know someone who would fit? stellenangebote.uni-marburg.de/jobposting/3...

"The Special Feature 'Half a Century of Cultural Evolution' assembles answers from a broad array of scientific disciplines with vastly different views on culture, but with one uniting theme: that culture evolves."

Open access

www.pnas.org/topic/565

The evolution of similarity-biased social learning | Evolutionary Human Sciences | Cambridge Core The evolution of similarity-biased social learning - Volume 7

It seems like a fitting, if dark, day to publish a paper on the adaptive value of parochialism. doi.org/10.1017/ehs....

I generally enjoy reviewing papers, especially in interdisciplinary venues, but the increasing number of method-in-search-of-a-problem papers is unfortunate. Especially since the methods are now complex Rube-Goldberg machines made out of LLMs.

Hilbert space methods for reduced-rank Gaussian process regression - Statistics and Computing This paper proposes a novel scheme for reduced-rank Gaussian process regression. The method is based on an approximate series expansion of the covariance function in terms of an eigenfunction expansio...

A colleague today asked about Gaussian Processes on a sphere. Like spatial autocorrelation on the globe. I asked @avehtari.bsky.social. There are papers! This problem common enough to be worth having a case study I think?
(1) Theory doi.org/10.1007/s112...
(2) Application doi.org/10.48550/arX...