Did you know that PHYSICAL STRENGTH is an important calibrator of behavioral strategies, attitudes, & psych disorders? 

Because: how 💪 a person is has massive effects on the cost-benefit calculus of decision-making across a range of social domains. 

🧵 re: strength & personality

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Across the animal kingdom, contests over resources are determined by physical fighting. The general principle is: A fight will escalate only far enough for one individual to determine that it will lose, then cede the resource to the more formidable individual. Thus, more formidable individuals are quicker to escalate conflicts &, in effect, have greater entitlement to contested resources. 

@AaronSell et al tested whether this applies to humans too. They found that physical strength, especially among men, positively associated with their anger proneness, entitlement, aggression, & behavioral history of fighting. 

2/13

What makes Sydney Sweeney’s body sexy enough to break the internet? 

If you know about any finding from evolutionary psychology, it’s as likely as any to be that, when it comes to women’s bodily attractiveness, a low (~.60-.70) waist-to-hip ratio (WHR) is optimal, contributing to a voluptuous hourglass shape. 

What you might not know about is the research that (1) sheds light on *why* low WHR is attractive, but also (2) challenges the centrality of WHR in defining women’s bodily attractiveness, (3) clarifies the (different) reproductive parameters indicated by waist size & hips size, respectively, & (4) tells us what, if anything, is going on with boobs. 

Thread 🧵
1/11
Women’s WHR has been hypothesized as an indicator of multiple reproduction-linked parameters, including fertility, youth, estrogen levels, health, and others. But it was never clear which, if any, of these drove the evolution of WHR preferences. 

Work by Lassek & Gaulin (2008) supports the hypothesis that fat stored on the gluteofemoral region (i.e. butt & thighs) is attractive because it is a critical neurodevelopmental resource in reproduction - the fat cells stored there are literally used to build babies brains during pregnancy! 

2/11

Across cultures, women are *much* higher than men on fearful personality traits. Why?

Our new SPPS paper—led by Joe Manson w/ Kristine Chua, @rodriguezNina_ @michael_barlev @durkeepk—provides an answer

tl;dr the sex diff in fear is mediated by that in physical strength

1/x Evidence supports the hypothesis that, b/c weaker people r more vulnerable 2 threats, the fear system’s activation threshold is calibrated 2 relative strength

@rodriguezNina_ & I showed this within sex: strong women(men) > fear than weak women(men)

2/x

drive.google.com/file/d/1abfm11…

@EvoRoseman @kohn_gregory @LTF_01 @rasmansa @EvolHumBehav @HumBehEvoSoc @Journal_EHS Ok, here is Tooby & Cosmides (2015) for a broad overview & review.

researchgate.net/profile/Leda-C… @EvoRoseman @kohn_gregory @LTF_01 @rasmansa @EvolHumBehav @HumBehEvoSoc @Journal_EHS Here is @aaron_sell @dsznycer @LaithAlShawaf et al (2017) presenting research on an adaptationist theory of anger

the-brights.net/morality/state…

Interested in human behavioral variation? You might check out this new theoretical+empirical paper in @EJPBlog by me, @DavidMGLewis @durkeepk Sell, @dsznycer, @ProfDavidBuss:

An Adaptationist Framework for Personality Science

Thread (Links below in 1st two comments)
1/14 Full text: drive.google.com/file/d/1z-kpu7…