Diego Guevara Beltran

🚨Very happy that my PhD work is now out in @nature.com!

We discovered that evolution, by acting in the midbrain, shifted the threshold to escape in Peromyscus mice, to fine-tune defensive strategies in different environments

www.nature.com/articles/s41...

This was a truly collaborative effort! 🧵⬇️

Some fun unpublished data from a talk I gave years ago on the sexual division of labor (SDOL) among the Batek of Malaysia.

The Batek have been described as highly gender-egalitarian.

Kirk and Karen Endicott collected the data in 1975-76, back when the Batek were fully nomadic foragers.

A preprint of this work can be found here: osf.io/preprints/ps... (10/10).

In follow-up work, we will examine sources of interdependence, shared fate, and cooperation (1) among dyads to study bidirectional (i.e., partner) effects, (2) whether shared fate guides partner-choice decisions, and (3) consequences for social integration & wellbeing (9/10).

Combined, results support the hypothesis that shared fate provides a proximate solution to partner choice dilemmas: Help partners to the extent that one has a positive stake in their welfare (8/10).

Finally, we show in a follow-up study with a subset of participants (N = 36, Obs. = 108) that shared fate is associated with helping more often in the past two weeks, and actual helping behavior (i.e., forgoing money to purchase a pound of rice for targets) (7/10).

We also find that shared fate statistically mediated all associations between relatedness and helping, suggesting shared fate is a key mechanism by which relatedness structures cooperation in this community (6/10).

However, at the within-person level, relatedness, sharing food (i.e., eating together), and shared subsistence activities (i.e., planting/harvesting, hunting/fishing) emerged as the most diagnostic cues of positive shared fate, and shared fate was associated with helping (5/10).

In bivariate correlations, we find that 8/10 sources of interdependence were correlated with higher shared fate, and shared fate correlated with more helping across 7 fitness-relevant domains (e.g., helping target's children, sharing crops) (4/10).

We wanted to test the idea that shared fate (e.g., "what is good for [target] is good for me") is a summary estimate of the degree to which people share a positive stake with others, and shared fate proximally guides helping towards positively interdependent partners (3/10).

We interviewed people (N = 146, Obs. = 437) about their sources of interdependence (e.g., relatedness, shared subsistence activities, commensality, co-residence, co-religiosity), shared fate, and helping towards an acquaintance, cousin, and a sibling (2/10).

How do people know whom, and how much, to help? we (@jessicadayers.bsky.social @leecronk.bsky.social Daniel Balliet @jeremykoster.bsky.social & @athenaaktipis.bsky.social) tackle this question among the Mayangna of northern Nicaragua, who rely primarily on horticulture for subsistence 🧵(1/10).

New Evidence Suggests Humans May Have Been Dipping Crunchy Things Into Gooey Things Earlier Than Previously Thought

New Evidence Suggests Humans May Have Been Dipping Crunchy Things Into Gooey Things Earlier Than Previously Thought theonion.com/new-evi...

🧵
Very excited (w/ @omarjcamanto.bsky.social) to share our preprint tutorial for using our R 📦 dySEM for #dyadic data analysis with latent variables, in cross-sectional data sets.

This paper has been literal years in the making, and provides three distinct tutorials.

osf.io/preprints/ps...

Reciprocity evolves more readily in competitive than cooperative socio-ecologies | Proceedings of the Royal Society B: Biological Sciences Tracking what others did and matching other’s expected actions is seen across a range of biological systems. As reciprocal matching rewards and reinforces cooperators and punishes and discourages non-...

🚨New article in Proc B:
"Reciprocity evolves more readily in competitive than cooperative socio-ecologies"

Using agent-based evolutionary models, we show that reciprocity emerges more reliably in competitive environments with high exploitation risk.

🔗 royalsocietypublishing.org/doi/10.1098/...

Added!

A unified framework integrating psychology and geography - Nature Human Behaviour In this Perspective, Götz et al. propose the unifying Geographical–Psychological Interactionist Framework, which aims to integrate psychology and geography to account for the context in which human be...

Psychology & geography need one another to fulfil their mandates, but integrating them has been empirically challenging. A new perspective by Götz et al proposes a unifying Geographical–Psychological Interactionist Framework to inspire concrete & testable hypotheses.
www.nature.com/articles/s41...

Targeting the Hunting Hypothesis: Review of Evidence From the Hadza The hunting hypothesis holds that ancestral human males favored their own mates and children in sharing meat gained from big game hunting, a practice said to have led to the origin of nuclear familie....

"grandmother hypothesis holds that senior women's foraging and food sharing led to life history changes that favored mate guarding, not paternal provisioning, in the formation of nuclear family-like social units" doi.org/10.1002/evan...

Added!

New paper alert! Sex and strife in our closest ape relatives

Our paper in @RSocPublishing shows that bonobos and chimpanzees overlap in their use of sex during social tension

-w Jake Brooker and coauthors inc the late Frans de Waal, his last paper

royalsocietypublishing.org/doi/10.1098/...

Yes, and, it includes other social and behavioral sciences (eg anthro, econ)

How do individual differences in trait empathy manifest in everyday state experiences of empathy? In a new preprint @minzlicht.bsky.social and I address this question: osf.io/preprints/ps.... We find theoretically expected trait-state relationships✅, but also some surprises😲. We also find trait 1/2

5) @psycheddiego.bsky.social extended interdependence research by surveying Mayangna participants to examine how shared fate impacts their cooperation. The more positive stake & shared fate in relationships, the more people tended to cooperate. #EPatSPSP2025 #SPSP2025

Last, some highlights from the #EPatSPSP2025 datablitzes:

1) A seriously cool talk by @wnmerrell.bsky.social about how we infer clustered (patchy) resource distribution based on an area’s hierarchicalness (& vice versa). Who knew lobstering could be so socially complex?! #SPSP2025

🚨Excited that our meta-analysis is out in JPSP @APA_Journals. We synthesized 6 decades (1958-2017) of empirical evidence on social dilemmas and tested which structural features (most strongly) promote cooperation:
doi.org/10.1037/pspi...
1/10

I hadn’t realized this until now, but in the prosociality and well-being lit, effective helping enhances the effect of helping on eg positive affect; I wonder how that might be compatible with signaling for eg reputation or if they’ve been tested?

Added!

1/8. This week I had a few different conversations with scholars who, in the face of the attacks on science and institutions of learning in the U.S., are wondering what to do. One suggestion I have is: keep doing your work. It matters in and of itself. Why do I say that? A few reasons.

Trump’s Border Czar Whines That Many Immigrants Are Smarter Than ICE Tom Homan is upset that ICE’s raids in Chicago aren’t as bad as they could be because many people know their rights.

2/8. Let me start with a recent example. The President’s “Border Czar” was recently furious because *checks notes* people have learned too much about their rights, which kept his team from exploiting them. Think about that. Knowing your rights is considered a threat.
www.yahoo.com/news/trump-b...

Maternal Depression: A Catalyst for Cooperation? - HBES Image: woman in Uganda – by Alessandra Cassar Women around the world experience maternal depression, particularly around the time of pregnancy and childbirth. With around 10-15% of mothers in high-inc...

"Women with more support from a loving and helpful partner were at significantly lower risk for depression. Conversely, conflicting or controlling relationships elevated the risk of depression"
www.hbes.com/maternal-dep...

#EvPsych #HBES