Graphical Abstract Schematic representation of challenges and perspectives for stress research during the COVID-19 pandemic. Stress researchers are forced to adapt established experimental procedures to current environmental demands or to develop new ones. Technologies that help adjust stress research to requirements of the COVID-19 pandemic, however, are not only temporary solutions but bear the potential to advance stress research far beyond the current situation. They give new perspectives to stress researchers by allowing research in new contexts, on special samples, and with new experimental variations. Created with BioRender.com.

No 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 By means of a systematic review, 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) and (ii) monozygotic-to-dizygotic twin Odds Ratios (48 studies, n = 63,295 individuals), both times for prevalence of left-, mixed-, and non-right-handedness. For monozygotic and dizygotic twin pairs we compared (iii) handedness 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, 95% Confidence Interval = [1.26, 1.57]) and non-right- (Odds Ratio = 1.36, 95% Confidence Interval = [1.22, 1.52]), but not mixed-handedness (Odds Ratio = 1.08, 95% Confidence Interval = [0.52, 2.27]) among twins compared to singletons. We further showed a decrease in Odds Ratios in more recent studies (post-1975: Odds Ratio = 1.30, 95% Confidence Interval = [1.17, 1.45]) compared to earlier studies (pre-1975: Odds Ratio = 1.90, 95% Confidence Interval = [1.59–2.27]). While there was (ii) no difference between monozygotic and dizygotic twins regarding prevalence of left- (Odds Ratio = 0.98, 95% Confidence Interval = [0.89, 1.07]), mixed- (Odds Ratio = 0.96, 95% Confidence Interval = [0.46, 1.99]), or non-right-handedness (Odds Ratio = 1.01, 95% Confidence Interval = [0.91, 1.12]), we found that (iii) handedness concordance was elevated among monozygotic compared to dizygotic twin pairs (Odds Ratio = 1.11, 95% Confidence Interval = [1.06, 1.18]). By means of moderator analyses, we did not find evidence for effects of potentially confounding variables. Conclusion We provide the largest and most comprehensive meta-analysis on handedness in twins. Although a raw, unadjusted analysis found a higher prevalence of left- and non-right-, but not mixed-handedness among twins compared to singletons, left-handedness was substantially more prevalent in earlier than in more recent studies. The single large, recent study which included birth weight, Apgar score and gestational age as covariates found no twin-singleton difference in handedness rate, but these covariates could not be included in the present meta-analysis. Together, the secular shift and the influence of covariates probably make it unsafe to conclude that twinning has a genuine relationship to handedness.

No abstract

Major life events can lead to changes in subjective well-being (SWB), but people differ in the extent and duration of these changes. Recent research indicates that individual differences in how people perceive major life events can explain some of these differences in event-related changes in SWB. But how events are perceived does not only vary between individuals, it also changes over time. Theories such as affective adaptation theory and appraisal theory suggest that such changes in the event perception are related to changes in SWB (life satisfaction, positive affect, and negative affect). The present article examined the dynamic interplay between perceived event characteristics and SWB using two longitudinal studies (NStudy1 = 619; NStudy2 = 691). In both studies, perceived event characteristics and SWB were assessed at two measurement occasions 3 months apart. We used bivariate latent change score models to estimate correlated changes of these constructs. Perceiving events as more externally controlled and as more social status threatening was consistently associated with a decrease in life satisfaction. Furthermore, perceiving events as more challenging over time was consistently associated with a decrease in positive affect and an increase in negative affect. Consequently, feedback loops between these constructs are a possible mechanism that explain event-related changes in SWB. Furthermore, our results highlight the importance of assessing perceived characteristics of major life events longitudinally to gain a better understanding of event-related changes in SWB.