The immune system can paradoxically mediate lethal effects when it is over-activated; an explanation is a function to restrict the cumulative risk of transmission of highly mutating environmental pathogens that may endanger species

To protect or to kill: a persisting Darwinian immune dilemma. Hugo O. Besedovsky, Adriana del Rey. Brain, Behavior, and Immunity, April 22 2022. https://doi.org/10.1016/j.bbi.2022.04.019

Abstract: The immune system, which evolved as a protective system, can paradoxically mediate lethal effects when it is over-activated. These effects can be traced back to infected insects and are mainly mediated by phylogenetically old cytokines that have been found already in starfishes and sponges. We hypothesize that these anti-homeostatic effects are important for restricting the cumulative risk of transmission of highly mutating environmental pathogens that may endanger species, particularly when they start to originate and expand. Considering the Darwinian view that evolution is a permanent process, this anti-homeostatic program is preserved and expressed even when there is no risk for the species. Here, we review these aspects and discuss how evolutionary-imposed anti-homeostatic immune programs are expressed during acute and chronic human diseases, which can be further aggravated in the absence of medical interventions. The relevance of early identification of ancestral biomarkers that predict a shift from protective to deleterious immune outcomes is emphasized.

The peak-end rule: When people retrospectively evaluate an experience (e.g., the previous workday), they rely more heavily on the episode with peak intensity and on the final (end) episode than on other episodes in the experience

All’s well that ends (and peaks) well? A meta-analysis of the peak-end rule and duration neglect. Balca Alaybek et al. Organizational Behavior and Human Decision Processes Volume 170, May 2022, 104149. https://doi.org/10.1016/j.obhdp.2022.104149

Highlights

• The peak-end rule is an efficient heuristic for evaluating past experiences.

• The meta-analytic peak-end effect is large and robust across moderators examined.

• The peak-end effect is stronger than the duration, beginning, and trough effects.

• The peak-end effect is stronger than the trend and variability effects.

• The peak-end effect is comparable to the overall average effect.

Abstract: The peak-end rule (Fredrickson & Kahneman, 1993) asserts that, when people retrospectively evaluate an experience (e.g., the previous workday), they rely more heavily on the episode with peak intensity and on the final (end) episode than on other episodes in the experience. We meta-analyzed 174 effect sizes and found strong support for the peak-end rule. The peak-end effect on retrospective summary evaluations was: (1) large (r = 0.581, 95% Confidence Interval = 0.487–0.661), (2) robust across boundary conditions, (3) comparable to the effect of the overall average (mean) score and stronger than the effects of the trend and variability across all episodes in the experience, (4) stronger than the effects of the first (beginning) and lowest intensity (trough) episodes, and (5) stronger than the effect of the duration of the experience (which was essentially nil, thereby supporting the idea of duration neglect; Fredrickson & Kahneman, 1993). We provide a future research agenda and practical implications.

Keywords: PeakEndTroughDuration neglectHeuristicsRetrospective evaluationsGestalt characteristics

Among white Americans, therefore, Democrats experienced a substantially greater increase in distress in response to the pandemic than Republicans

Distressed Democrats and relaxed Republicans? Partisanship and mental health during the COVID-19 pandemic. Sean Bock, Landon Schnabel. PLoS April 21, 2022. https://doi.org/10.1371/journal.pone.0266562

Abstract: The COVID-19 pandemic was a potent stressor, yielding unprecedented levels of mental distress. However, public health responses and personal reactions to the pandemic were politically polarized, with Democrats highlighting and Republicans downplaying its severity. Did Republicans subsequently experience as much mental distress as Democrats during the COVID-19 pandemic? This study examines partisan patterns in mental health outcomes at three time points throughout the pandemic. Results demonstrate a clear partisan distress gap, with Democrats consistently reporting worse mental health than Republicans. Trend data suggest that the 2020 pandemic patterns are a continuation and exacerbation of an existing partisan distress gap. Consideration of race, however, demonstrates a widening partisan distress gap, specific to white Americans. Among white Americans, therefore, Democrats experienced a substantially greater increase in distress in response to the pandemic than Republicans.

Conclusion

The COVID-19 pandemic acted as a powerful stressor, leading to increased distress among Americans. Distress during the pandemic was politically polarized, however, such that Democrats reported consistently higher distress levels compared to Republicans, suggesting a clear partisan distress gap. This gap did not simply emerge as a result of the pandemic, but rather reflects a pre-existing partisan distress gap. Yet, marked intra-party variation in experiences with the pandemic results in a more nuanced story: White Democrats experienced the largest increase in distress along several measures from the pandemic, which produced a widening distress gap among white partisans. Further, over-time data show the pandemic accelerated a long-running trend of a closing of the racial happiness gap among Democrats. Whereas the partisan gap used to be disproportionately driven by the unhappiness of black Democrats, it is now driven primarily by the unhappiness of white Democrats. These patterns highlight the importance of race for trends in partisanship and polarization more generally.

The results point to several possible extensions. The data for this study are from the summer of 2020, before widespread vaccine roll out. As the pandemic wears on, we are experiencing a mental health crisis. Isolation, distress about the present, and uncertainty about the future—not to mention lost friends and family—are taking a toll. Partisan vaccine uptake further highlights the partisan nature of pandemic response, but it may have changed the equation in ways that should be examined in future research. With vaccines, Democrats may be able to regain some of the normalcy and connections they lost in isolation. And serious illness and death have become visibly partisan with the vaccines, and the greater loss experienced among Republicans, and perhaps eventual acceptance of COVID-19 as a real threat and the pandemic something to worry about, may fuel greater distress among them than in the past. Beyond the partisan nature of mental wellbeing in the pandemic, we hope this study will motivate future research on race (and ethnicity) in these processes more generally. These data were effective for highlighting race trends between black and white Americans over decades and future research should further disentangle racial and ethnic trends in partisanship and distress among and between more groups.