The Religion & Spirituality Preconference at @spspnews.bsky.social 2027 is now accepting applications! We're excited for a full day of programming, including talks from @conradhackett.bsky.social, Patty Van Cappellen, Kristin Laurin, & @lfitouchi.bsky.social. More here! 📣 spsp.org/events/annua...
Matthew I. Billet
@matthewibillet.bsky.social
Culture | Religion | Social Cognition | Environmental Decision Making Postdoc UC Irvine | PhD S/P Psychology University of British Columbia
What is a psychological theory? Here's our take on this tricky and controversial question in this week's Experimentology chapter summary. Many things called "theories" in psychology aren't actually theories — they're frameworks. 🧵 experimentology.io
This report, unfortunately, is timed perfectly with the release of my new JPSP article on apocalyptic thinking. Apocalyptic rhetoric is not new, and we are beginning to understand the psychology underlying it. Pre-print available free on my website: www.matthewibillet.com dx.doi.org/10.1037/pspi...
EXCLUSIVE: At more than 30 installations, U.S. commanders told troops the war on Iran is a Christian war. The Military Religious Freedom Foundation has been “inundated” with more than 110 complaints. One NCO said they were told the U.S. war is to bring about Armageddon and the return of Jesus…
New article in JPSP on Apocalyptic Thinking! Takeaways in the title: End of world beliefs are common, diverse, and predict how people perceive and respond to global risks. Cindel J.M. White, @azimshariff.bsky.social & Ara Norenzayan. @ucirvine.bsky.social @psych.ubc.ca @spspnews.bsky.social 1/5
What motivates people to engage in climate advocacy? In a new PNAS Nexus megastudy [https://doi.org/10.1093/pnasnexus/pgaf400] led by @dgoldwert.bsky.social we tested 17 theoretical interventions on a large US sample (N=31,324) to increase public, political, and financial climate advocacy. 1/5
Revision posted! An evolutionary model of identity signaling with nested/overlapping/intersectional identities, complex multidimensional signaling capabilities, and a primer on ancient Mesopotamia. What more could you ask for? osf.io/preprints/so...
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...
New pre-print analyzing 25,000 Christian sermon transcripts across the USA. Churches account for most systematic variance in sermon content, geographic region accounts for none. We identify niches in sermon content that may guide religious competition in USA. osf.io/preprints/ps...
OSF
osf.io
Interested in the psychology of people's spiritual connections with nature, and how it shapes well-being and sustainable behavior? Check out my open-access Current Directions article with Adam Baimel (@abaimel.bsky.social), Mark Schaller, and Ara Norenzayan: journals.sagepub.com/doi/full/10....
Ecospirituality - Matthew I. Billet, Adam Baimel, Mark Schaller, Ara Norenzayan, 2025
Many people in many cultures have a spiritual connection with nature. Research is beginning to reveal the implications of this “ecospiritual” orientation for tw...
journals.sagepub.com
Below is my new post about our Three Stages of Religious Decline paper (www.nature.com/articles/s41...). We argue that a similar process of decline affects countries on every populated continent, including countries in which Christianity, Islam, Buddhism or Hinduism is the largest religion. A🧵
How religion declines around the world
A country’s religious affiliation tends to decline in three transitional stages that unfold across generations, a new paper using Center data proposes.
pewresearch.org
An incredible resource on Social Psychology today spanning 50 beefy chapters written by some of the greatest scholars today. The best part is, the new Handbook of Social Psychology is completely free and available online to download. Here's the link. openpublishing.princeton.edu/projects/the...
The Handbook of Social Psychology (6th Edition) in PDF | The Handbook of Social Psychology | Open Publishing
<b>You can download individual chapters and/or the complete book in PDF below.</b><br><br> <i>The Handbook</i> is designed to be read online as a continuous-scroll e-book. PDFs may contain inelegant p...
openpublishing.princeton.edu
Fully-funded PhD position on the cultural evolution of environmental management! Link evolution, ecology and behavioral science in the ACE Lab timwaring.info Details: forms.gle/gZWK9BpwYfoG... @culturalevolsoc.bsky.social @alexmesoudi.com @hyperadapthyrax.bsky.social @michael.muthukrishna.com
ACE Lab: Applied Cultural Evolution Laboratory
culture, evolution, cooperation, and sustainability
timwaring.info
After a long wait, the working paper for the Many-Economists Project: The Sources of Researcher Variation in Economics. We had 146 teams perform the same research three times, each time with less freedom. What source of freedom leads to different choices and results? papers.ssrn.com/sol3/papers....
The Sources of Researcher Variation in Economics
We use a rigorous three-stage many-analysts design to assess how different researcher decisions—specifically data cleaning, research design, and the interpretat
papers.ssrn.com
How can we sustain both our planet and ourselves? Drawing on a new review of research by @matthewibillet.bsky.social, @abaimel.bsky.social, and colleagues - as well as faith and climate scientist leaders like @katharinehayhoe.com, my article for @psychologytoday.com explores what we can do.
The New Science of Ecospirituality
How can we sustain both our planet and ourselves? The new science of ecospirituality has some ideas and some suggestions to try.
psychologytoday.com
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...
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 🧵
Critical comms about climate change is increasingly happening on social media. But it is challenging to study climate comms on popular social media platforms, so researchers often rely on survey research. How much do survey responses tell us how things will play out on social media? Thread 🧵
Does anyone have recommendations for more recent textbooks on environmental psych / conservation psych? I love this one by Gardner and Stern, but it's quite outdated now. #APA34 #environmentalpsych #conservationpsych #sustainability
Check out our new article on ecospirituality! Takeaways: Ecospirituality is associated with environmental concern and well-being, and changes in ecospirituality are associated with changes in these variables too! (plus a large pre-registered outdoor experiment that kinda failed!)
New in Social Psychology: Seeing Nature Through a Spiritual Lens: An Experimental Test of the Effects of a Novel Photo-taking Task on Environmental Concern and Well-being, from @matthewibillet.bsky.social et al. doi.org/10.1525/coll...
Very interesting results in this new meta-analysis of why people turn to conspiratorial thinking. Conspiratorial thinking is a response to external threats, not really a trait of specific kinds of people. I want to know... 1/2
🚨Our meta-analysis of the motives associated with conspiracy beliefs has been accepted at Psychological Bulletin!🚨“Reasons to believe: A systematic review and meta-analytic synthesis of the motives associated with conspiracy beliefs” osf.io/preprints/ps... 🧵👇 1/16
New open access article assessing the common ground between liberals and conservatives on why nature is worth preserving. Turns out they share a lot in common! I did this work with Adam Baimel (@abaimel.bsky.social ), Taciano Milfont, and Ara Norenzayan. 1/n journals.sagepub.com/doi/10.1177/...
{ggeffects} version 2.0.0 is out now! Read more about this #rstats package at strengejacke.github.io/ggeffects What does {ggeffects} do? The 📦 helps you to understand (complex) models and results by calculating and plotting *estimated marginal means* or more generally, *adjusted predictions*. 🧵
Create Tidy Data Frames of Marginal Effects for ggplot from Model Outputs
Compute marginal effects and adjusted predictions from statistical models and returns the result as tidy data frames. These data frames are ready to use with the ggplot2-package. Effects and predictio...
strengejacke.github.io