Cultural values emphasizing the desire to acquire status, as well as cultures values devaluing similarity with others & gender egalitarianism, predict higher levels of competitiveness toward members of one’s own gender

Buunk, A. P. (2020). Cultural dimensions associated with intrasexual competitiveness. Evolutionary Behavioral Sciences, Mar 2021. https://doi.org/10.1037/ebs0000233

Abstract: In the present study among 80 exchange students from 30 countries studying in The Netherlands, I examined how intrasexual competitiveness (ISC), that is, a competitive attitude toward members of one’s own gender, was associated with various cultural dimensions. A multiple regression analysis showed that vertical individualism predicted ISC positively and that horizontal collectivism predicted ISC negatively. That is, the higher individuals were in ISC, the more likely they came from cultures accepting inequality and status differences as a law of nature and the less likely they came from cultures emphasizing the similarity of members of their own culture. In addition, data independently collected showed that ISC was typical for those from cultures with a low level of gender egalitarian values. I conclude that cultural values emphasizing the desire to acquire status, as well as cultures values devaluing similarity with others and gender egalitarianism, predict higher levels of ISC.

Robust evidence that monozygotic twins are more likely to be concordant for handedness than dizygotic twins; this finding supports a partially genetic determination of handedness

Pfeifer, Lena S., Judith Schmitz, Marietta Papadatou-Pastou, Jutta Peterburs, Silvia Paracchini, and Sebastian Ocklenburg. 2021. “Handedness in Twins: Meta-analyses.” PsyArXiv. March 12. doi:10.31234/osf.io/gy2nx

Abstract

Background: In the general population, 10.6 % of people favor their left hand over the right for motor tasks. Previous research suggests higher prevalence of atypical (left-, mixed-, or non-right-) handedness in (i) twins compared to singletons, and in (ii) monozygotic compared to dizygotic twins. Moreover, (iii) studies have shown a higher rate of handedness concordance in monozygotic compared to dizygotic twins, in line with genetic factors playing a role for handedness.

Methods: We identified 59 studies from previous literature and performed three sets of random effects meta-analyses on (i) twin-to-singleton Odds Ratios (21 studies, n = 189,422 individuals), (ii) monozygotic-to-dizygotic twin Odds Ratios (48 studies, n = 63,295 individuals), and (iii) concordance Odds Ratios (44 studies, n = 36,217 twin pairs). We also tested for potential effects of moderating variables such as sex, age, the method used to assess handedness and the twins’ zygosity.

Results: We found (i) evidence for higher prevalence of left- (Odds Ratio = 1.40) and non-right- (Odds Ratio = 1.36), but not mixed-handedness (Odds Ratio = 1.08) among twins compared to singletons. We further showed a reduction of difference over time, which suggests that higher levels of left-handedness observed in twins are linked to a higher frequency of birth complications which might have dropped nowadays in their overall prevalence because of better healthcare. While there was (ii) no difference between monozygotic and dizygotic twins regarding prevalence of left- (Odds Ratio = 0.98), mixed- (Odds Ratio = 0.96), or non-right-handedness (Odds Ratio = 1.01), we found that (iii) handedness concordance was elevated among monozygotic compared to dizygotic twin pairs (Odds Ratio = 1.11). Moderator analyses showed our results to be robust against potentially confounding variables.

Conclusion: We provide the largest and most comprehensive meta-analysis on handedness in twins. Results suggest that the previously reported effect that twins are more likely to be left-handed than singletons is robust. Furthermore, we also provide robust evidence that monozygotic twins are more likely to be concordant for handedness than dizygotic twins. In line with recent genome-wide association studies, this finding supports a partially genetic determination of handedness.

A memory must be malleable to maintain its predictive value in a dynamic environment; after being retrieved, a consolidated memory may become susceptible to updating (via reconsolidation, extinction, or forgetting)

Understanding the dynamic and destiny of memories. Lucas de Oliveira Alvares, Fabricio H. Do-Monte. Neuroscience & Biobehavioral Reviews, March 12 2021. https://doi.org/10.1016/j.neubiorev.2021.03.009

Highlights

• A memory must be malleable to maintain its predictive value in a dynamic environment.

• After being retrieved, a consolidated memory may become susceptible to modifications.

• Retrieval can lead to memory updating via reconsolidation, extinction, or forgetting.

• These post-retrieval memory destinies involve distinct neural circuits and mechanisms.

• Memory updating has important biological functions including behavioral adjustment.

Abstract: Memory formation enables the retention of life experiences overtime. Based on previously acquired information, organisms can anticipate future events and adjust their behaviors to maximize survival. However, in an ever-changing environment, a memory needs to be malleable to maintain its relevance. In fact, substantial evidence suggests that a consolidated memory can become labile and susceptible to modifications after being reactivated, a process termed reconsolidation. When an extinction process takes place, a memory can also be temporarily inhibited by a second memory that carries information with opposite meaning. In addition, a memory can fade and lose its significance in a process known as forgetting. Thus, following retrieval, new life experiences can be integrated with the original memory trace to maintain its predictive value. In this review, we explore the determining factors that regulate the fate of a memory after its reactivation. We focus on three post-retrieval memory destinies (reconsolidation, extinction, and forgetting) and discuss recent rodent studies investigating the biological functions and neural mechanisms underlying each of these processes.

Keywords: Memory updatingReconsolidationExtinctionforgettingretrieval

The Intended and Unintended Consequences of Disposable Bag Regulation

Skipping the Bag: The Intended and Unintended Consequences of Disposable Bag Regulation. Tatiana Homonoff, Lee-Sien Kao, Javiera Selman & Christina Seybolt. NBER Working Paper 28499, February 2021. DOI 10.3386/w28499

Abstract: Regulation of goods associated with negative environmental externalities may decrease consumption of the targeted product, but may be ineffective at reducing the externality itself if close substitutes are left unregulated. We find evidence that plastic bag bans, the most common disposable bag regulation in the US, led retailers to circumvent the regulation by providing free thicker plastic bags which are not covered by the ban. In contrast, a regulation change that replaced the ban with a small tax on all disposable bags generated large decreases in disposable bag use and overall environmental costs. Our results suggest that narrowly-defined regulations (like plastic bag bans) may be less effective than policies that target a more comprehensive set of products, even in the case when the policy instrument itself (a tax rather than a ban) is not as strict.

Meta-analysis: The amygdala is significantly involved in the ha-ha experience of decoding punchlines

Humor and emotion: Quantitative meta analyses of functional neuroimaging studies. Andrew H. Farkas et al. Cortex, March 11 2021. https://doi.org/10.1016/j.cortex.2021.02.023

Highlights

• Large meta-analysis of brain activation driven by humor versus control stimuli.

• Humor activates areas linked with language, theory of mind, & knowledge integration.

• Humor cue modality (picture, text, laughter) modulates brain network activation.

• Complex humor activates supramodal areas of the brain associated with emotion.

Abstract: Humor is a ubiquitous aspect of human behavior that is infrequently the focus of neuroscience research. To localize human brain structures associated with the experience of humor, we conducted quantitative activation likelihood estimate (ALE) meta analyses of 57 fMRI studies (n=1248) reporting enhanced regional brain activity evoked by humorous cues versus matched control cues. We performed separate ALE analyses of studies that employed picture-driven, text-based, and auditory laughter cues to evoke humor. A primary finding was that complex humor activates supramodal areas of the brain strongly associated with emotional processes, including bilateral amygdala and inferior frontal gyrus. Moreover, activation in brain regions associated with language, semantic knowledge, and theory of mind were differentially modulated by text and picture-driven humor cues, while hearing laughter enhances activation in auditory association cortex. The identification of humor-driven brain networks has the potential to expand brain-derived models of human emotion and could provide useful targets in translational research and therapy.

Keywords: humorhumouremotionmeta-analysishumanneuroimaging