Friday, April 6, 2018

Handgrip strength predicts measures of aggression & social dominance, perceived formidability, male-typical body morphology & movement, courtship display, physical attractiveness, & sexual behavior & reproductive fitness

Handgrip Strength as a Darwinian Fitness Indicator in Men. Andrew C. Gallupand Bernhard Fink. Frontiers in Psychology, https://doi.org/10.3389/fpsyg.2018.00439

Handgrip strength (HGS) is a robust measure of overall muscular strength and function, and has long been predictive of a multitude of health factors and physical outcomes for both men and women. The fact that HGS represents such a ubiquitous measure of health and vitality may reflect the significance of this trait during human evolution. This trait is also highly sexually dimorphic due to influences of androgenic hormones and fat-free body mass, suggesting that it has been further elaborated through sexual selection. Consistent with this view, research within evolutionary psychology and related fields has documented distinct relationships between HGS and measures of social and sexual behavior, especially in men. Here, we review studies across different societies and cultural contexts showing that male HGS predicts measures of aggression and social dominance, perceived formidability, male-typical body morphology and movement, courtship display, physical attractiveness, and sexual behavior and reproductive fitness. These findings underscore the value of including HGS as an independent measure within studies examining human sexual selection, and corroborate existing research suggesting that specific features of physical strength have and continue to be under positive directional selection in men.

h/t: https://twitter.com/DegenRolf

Incomplete physics and the finite representation of computers can induce false instabilities; eliminating instability can lead to computational overstabilization or false stability. Models on ultra-long timescales are dubiously stable. This is referred to as the “climate state.”

Christopher Essex and Anastasios A.Tsonis (2018) Model falsifiability and climate slow modes, Physica A, Volume 502, July 2018, Pages 554-562. https://doi.org/10.1016/j.physa.2018.02.090

Highlights
• Climate models do not and cannot employ known physics fully. Thus, they are falsified, a priori.
• Incomplete physics and the finite representation of computers can induce false instabilities.
• Eliminating instability can lead to computational overstabilization or false stability.
• Models on ultra-long timescales are dubiously stable. This is referred to as the “climate state.” Is it real?
• Decadal variability is understandable in terms of a specific class of nonlinear dynamical systems.

Abstract: The most advanced climate models are actually modified meteorological models attempting to capture climate in meteorological terms. This seems a straightforward matter of raw computing power applied to large enough sources of current data. Some believe that models have succeeded in capturing climate in this manner. But have they? This paper outlines difficulties with this picture that derive from the finite representation of our computers, and the fundamental unavailability of future data instead. It suggests that alternative windows onto the multi-decadal timescales are necessary in order to overcome the issues raised for practical problems of prediction.

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Prof. Essex explains,

“Unlike the stable virtual ‘climates’ seen in computer simulations, corresponding real-world conditions aren’t stable at all. There are perpetual, natural, internal changes in play that take longer than human lifetimes to play out.”

No human will ever fully perceive this change. No one lives long enough.  But some astute people, in their later years, might just be able to make a little of it out.

Prof. Essex adds,

“There is an ultraslow, mysterious, unseen world out there, under our very noses, that we cannot perceive. It’s beyond our measurement capabilities, and beyond the capabilities of our best computers using our very best physical theories. It belongs to a class of problems that we cannot overwhelm with data, or crush with our biggest computers.”

Nevertheless, there is hope. As Professor Tsonis explains, our growing understanding of the nature of natural ocean modes  and how they are linked may open up a whole new field of research into ultra-long timescales taking us beyond the virtual stability of modified meteorological models:

“Ocean modes like the North Atlantic Oscillation and the Pacific Decadal Oscillation, known natural internal dynamical features, affect weather patterns globally over years, decades and longer. They are deep structures that are coming to be understood on their own terms. We understand better than ever how they are linked, and we understand the mathematical structures in play in ways that we could not have only a few decades ago. We are on the verge of being able to predict what they will do next. If we succeed, a hitherto invisible world will open to us. We will see new wonders through new eyes.”

Differential relationship of jumping-to-conclusions and incorrigibility with delusion severity

Differential relationship of jumping-to-conclusions and incorrigibility with delusion severity. Christina Andreou, Ruth Veckenstedt, Thies L├╝dtke, Vasilis P. Bozikas, Steffen Moritz. Psychiatry Research, https://doi.org/10.1016/j.psychres.2018.04.014

Highlights
•We investigated trait and state aspects of jumping-to-conclusions and incorrigibility
•The two reasoning biases showed differential associations with delusion severity
•Results suggest different roles of the two biases in delusion formation / maintenance

Abstract: Reasoning biases such as jumping-to-conclusions (JTC) and incorrigibility have been suggested to contribute to the generation and maintenance of delusions. However, it is still debated whether these biases represent stable traits of patients with delusions, or are related to state fluctuations in delusion severity. The present study aimed to elucidate this question by combining a cross-sectional with a longitudinal approach. JTC, incorrigibility and delusion severity were assessed in 79 patients with a history of delusions over a 6-month period. To allow for a differentiated look into effects of time vs. symptom changes, patients were divided into patients with (D+) and without (D-) current delusions at baseline. Significant improvement of delusions was noted in D+ at follow-up. JTC did not differ between the two patient groups either at baseline or over time. In contrast, incorrigibility was significantly higher in D+ than D- at baseline; this difference remained stable throughout the 6-month follow-up period. The two biases did not significantly co-vary over time. Our results suggest a dissociation between incorrigibility and JTC as regards their relation to current presence of delusions, and tentatively support theoretical accounts attributing different roles to the two biases in the generation (JTC) and maintenance (incorrigibility) of delusions.

Keywords: Reasoning biases, Cognitive biases, Jumping-to-conclusions, Belief flexibility, Bias against disconfirmatory evidence, Psychosis

h/t: https://twitter.com/DegenRolf

Niels Bohr suggested that willed actions come with slower movement execution than reactions, and therefore that a film’s hero is able to get the upper hand even though the villain normally draws first. This is due to independent systems for willed (the bad guy's) and reactive (the hero's) movements

Disarming the gunslinger effect: Reaction beats intention for cooperative actions. Lisa Weller, Wilfried Kunde, Roland Pfister. Psychonomic Bulletin & Review, https://link.springer.com/article/10.3758/s13423-018-1462-5

Abstract: According to the famous physicist Niels Bohr, gunfights at high noon in Western movies not only captivate the cinema audience but also provide an accurate illustration of a psychophysical law. He suggested that willed actions come with slower movement execution than reactions, and therefore that a film’s hero is able to get the upper hand even though the villain normally draws first. A corresponding “gunslinger effect” has been substantiated by empirical studies. Because these studies used a markedly competitive setting, however, it is currently unclear whether the gunslinger effect indeed reflects structural differences between willed actions and reactive movements, or whether it is a by-product of the competitive setting. To obtain bullet-proof evidence for a true reactive advantage, we investigated willed and reactive movements during a cooperative interaction of two participants. A pronounced reactive advantage emerged, indicating that two independent systems indeed control willed and reactive movements.