Rather than the crisis fundamentally changing people psychologically, genetic differences between individuals seem to play a fundamental role in shaping psychological & behavioural responses to the COVID-19 crisis

Genetic correlates of psychological responses to the COVID-19 crisis in young adult twins in Great Britain. Kaili Rimfeld et al. Aug 2020. https://doi.org/10.21203/rs.3.rs-31853/v1

Abstract: We investigated how the COVID-19 crisis and the extraordinary experience of lockdown affected young adults in England and Wales psychologically. One month after lockdown commenced (T2), we assessed 30 psychological and behavioural traits in 4,000 twins in their mid-twenties and compared their responses to the same traits assessed in 2018 (T1). Mean changes from T1 to T2 were modest and inconsistent: just as many changes were in a positive as negative direction. Twin analyses revealed that genetics accounted for about half of the reliable variance at T1 and T2. Genetic factors correlated on average .86 between T1 and T2 and accounted for over half of the phenotypic stability. Systematic environmental influences had negligible impact on T1, T2 or T2 change. Rather than the crisis fundamentally changing people psychologically, our results suggest that genetic differences between individuals play a fundamental role in shaping psychological and behavioural responses to the COVID-19 crisis.

Keywords: COVID-19, lockdown, psychological and behavioural traits, twins, young adults, England and Wales


Discussion

How much has the COVID-19 crisis changed young adults psychologically following the unprecedented social experiment of one month of lockdown? As expected, the 30 measures in our study yielded many statistically significant changes in means. The largest changes in the negative direction were reduced volunteering and achievement motivation and increased hyperactivity-inattention. However, there were as many changes in the positive direction, most notably, reduced verbal peer victimisation. Changes were similar in direction and magnitude for males and females, with the single exception of general anxiety, which increased more for females than males. However, most of these mean changes have modest effect sizes, with an average d of 0.24. Although we expected that the crisis would affect some individuals more than others, we found no increase in variance at T2.  It is possible that the effects of the crisis will hit harder later or that longer lockdown or the economic aftermath of the crisis will have a greater effect. We will investigate these possibilities with three follow-up surveys during 2020.

Why do these young adults in Great Britain show modest negative effect on average after being in lockdown for one month when it is generally assumed that the psychological effects will be substantial? Part of the answer is that research often focuses on statistical significance and mean differences rather than considering effect size and individual differences. With our large sample size, nearly all variables show significant mean differences, but they don’t make much of a difference, accounting for less than two percent of the variance on average. Another reason might be methodological. In the present study we did not focus on participants’ subjective reports of how the COVID-19 crisis changed them. Instead, at T2, we asked participants to report, for example, how depressed they felt during the month following lockdown, which we compared to their reports of depression on the same measures in 2018. We found no difference in depression on average.

Other reasons why we found few negative effects of the COVID-19 crisis could be that the lockdown was so widespread (we’re all in it together spirit?) or that our participants are British (stiff upper lip?) or that they are young adults (resilience? insouciance?). Concerning the insouciance hypothesis, we asked participants at T2 how much they were worried about their physical health and mental health during the month since lockdown. The frequency of those reporting that they were moderately, very, or extremely worried was 38% for physical health and 57% for mental health. In other words, they were, quite reasonably, worried, although on average they did not change psychologically, including their symptoms of general anxiety. This can be viewed as a hopeful message that young people on average, are resilient psychologically to an experience as seismic as COVID-19 and lockdown, although these mean differences mask individual differences to the COVID-19 and lockdown. It remains to be seen if similar results emerge in other countries, at other ages and after longer exposure to the crisis and its aftermath.

The focus of our study was on individual differences rather than mean differences. How much has COVID-19 shuffled the deck of individual differences? The rank order of individual differences was largely stable from T1 to T2, with stability accounting for about 70% of the reliable variance at T1 and T2 on average across the measures. From a genetic perspective, the most interesting finding was that the average genetic correlation was 0.86, indicating that genetic effects at T1 were highly correlated with genetic effects at T2, despite the intervening COVID-19 crisis and lockdown. It is also interesting that T2 changes, which are independent of T1, show genetic influence.

We conclude that inherited DNA differences are the major systematic force shaping individual differences in psychological traits at T2 as well as at T1. Genetic effects account for about half of the reliable psychological differences between people at T1 and T2. The environment accounts for the rest of the variance, but it is not the systematic effect of environmental factors often assumed to be important, such as shared family environment. Environmental factors of this systematic sort had negligible effects on variance at T1 and T2 and for T2 change. The environmental effects that make a difference are those that are not shared by twin siblings growing up in the same family or, in our study, by twins locked down together. These idiosyncratic ‘non-shared’ environmental factors are likely to be unsystematic, chance experiences (Plomin, 2018).

Our results confirmed seven of our eight pre-registered (https://osf.io/r58be/) hypotheses. This speaks to the replicability of findings from behavioural genetic research on which these hypotheses were based, which is noteworthy given the replication crisis in science in general and in psychology in particular (Plomin et al., 2016). The exception was the hypothesis that variance at T2 would be greater than at T1, which was a prediction not based on behavioural genetic research. The consistency of results from T1 to T2 also attests to the replicability of research in behavioural genetics.

Concluding that inherited DNA differences are the major systematic force shaping who we are psychologically does not imply that novel environmental interventions, including therapeutic interventions, cannot make a difference. It should be emphasised that heritability does not imply immutability.

Heritability is a descriptive statistic limited to a particular population at a particular time with a particular mix of genetic and environmental influences. Our study can be seen as an attempt to assess whether heritability changed as a function of a tectonic shift in environment, the COVID-19 crisis.

Concluding that the COVID-19 crisis has not fundamentally changed these young people psychologically is not to dismiss the pain some of them felt before or during the crisis, or will continue to feel after the crisis ends. Even though the crisis had little effect on means and even less effect on variances and covariances, genetically driven psychological vulnerabilities are especially important targets for preventive interventions in young adults because the twenties is a pluripotent tipping point for life-long psychological problems (Arnett, 2014; Smith et al., 2011).

Imagining the future, remembering the past: Future events were simulated at proportionally higher speed than past events; the density of experience units representing the unfolding of events was lower for future episodes

The temporal compression of events during episodic future thinking. Olivier Jeunehomme, Nathan Leroy, Arnaud D'Argembeau. Cognition, August 6 2020, 104416. https://doi.org/10.1016/j.cognition.2020.104416

Highlights
• The unfolding of real-world events is temporally compressed in future simulations.
• Compression rates are higher for future than past events.
• Compression rates are lower for actions than spatial displacements.
• Temporal compression depends on the density of represented experience units.
• Experience units serve as an index for estimating past and future event durations.

Abstract: While the cognitive and neural mechanisms that underlie episodic future thinking are increasingly well understood, little is known about how the temporal unfolding of events is represented in future simulations. In this study, we leveraged wearable camera technology to examine whether real-world events are structured and compressed in the same way when imagining the future as when remembering the past. We found that future events were simulated at proportionally higher speed than past events and that the density of experience units representing the unfolding of events was lower for future than for past episodes. Despite these differences, the nature of events influenced compression rates in the same way for past and future events. Furthermore, the perceived duration of both types of events depended on the density of represented experience units. These results provide novel insight into the mechanisms that structure the unfolding of events during future simulations.

Keywords: Episodic memoryEpisodic future thinkingTemporal compressionTime estimationWearable camera

Trait mindfulness do not reliably translate into a pattern of healthful behaviours in general, although trait mindfulness shows a stronger associations with health behaviours under certain conditions

Trait mindfulness and health behaviours: a meta-analysis. Margarita Sala ,Catherine Rochefort,P. Priscilla Lui &Austin S. Baldwin. Health Psychology Review, Volume 14, 2020 - Issue 3, Pages 345-393, Aug 11 2019. https://doi.org/10.1080/17437199.2019.1650290

ABSTRACT: Mindfulness is defined as bringing one’s attention to present-moment experience with acceptance, and is associated with engagement in various health behaviours. To synthesise and evaluate this literature, we conducted a comprehensive meta-analytic review and examined (a) the associations between trait mindfulness and health behaviours and (b) the extent to which these associations were moderated by study and individual differences. A total of 125 independent samples were included (N = 31,697, median male percentage = 38.8%, median age = 28.3). A multilevel random-effects model was used to estimate summary study-level effect sizes, and multilevel mixed-effects models were used to examine moderator effects. Mindfulness had a positive and small association with aggregated health behaviours (r = .08). Mindfulness was positively associated with physical activity, healthy eating, and sleep (rs = .08–.14), and negatively associated with alcohol use (r = −.06). Effects were larger for health promoting behaviours, the acting with awareness facet of mindfulness, and samples involving psychiatric patients. Although findings indicate that individual differences in trait mindfulness do not reliably translate into a pattern of healthful behaviours in general, trait mindfulness shows a stronger associations with health behaviours under certain conditions.

KEYWORDS: Mindfulness, physical activity, healthy eating, sleep, substance use

Increasing Population Densities Predict Decreasing Fertility Rates over Time: A 174-nation Investigation

Rotella, Amanda M., Michael E. W. Varnum, PhD, Oliver Sng, and Igor Grossmann. 2020. “Increasing Population Densities Predict Decreasing Fertility Rates over Time: A 174-nation Investigation.” PsyArXiv. August 5. doi:10.31234/osf.io/zpc7t

Abstract: Fertility rates have been declining worldwide over the past five centuries, part of a phenomenon known as “the demographic transition”. Prior work suggests that this decline is related to population density, however to date this work has either been largely atheoretical or cross sectional. We draw on life history theory to examine the relationship between population density and fertility over time both within and between countries across 174 countries over 69 years (1950 to 2019) using annual data. Using state-of-the-art methods, we find a robust relationship between density and fertility; increased population densities are associated with lower fertility rates, controlling for a variety of socioeconomic, socioecological, geographic, cultural, population-based, and female empowerment related variables. Importantly, we also generate predictions about the conditions in which this effect should be stronger vs. weaker. Consistent with these predictions, we find that where conditions are harsh and favor engagement in shorter-term strategies (i.e., high homicide rates, low GDP per capita, high economic inequality, and high pathogen prevalence), the effect of increased population density on fertility rates is attenuated. We also find that the density-fertility relationship is moderated by religiousness and strength of social norms. These findings shed new light on why, and under what conditions, rising population densities influence fertility rates.

Intelligence manifests itself in the brain in breaking a problem down into multiple subtasks, which are worked on in widely distributed processing units, showing signs of being focused on the common plan

Integrated Intelligence from Distributed Brain Activity. John Duncan, Moataz Assem, Sneha Shashidhara. Trends in Cognitive Sciences, August 5 2020. https://doi.org/10.1016/j.tics.2020.06.012

Highlights
.  Fluid intelligence tests predict success in many activities, suggesting cognitive mechanisms of broad importance.
.  We propose a core process of attentional integration. Complex problems must be segmented into simpler parts. Attention to each part integrates cognitive fragments into a computational structure.
.  Fluid intelligence is linked to the brain’s multiple-demand (MD) system, defined by common activity across different cognitive demands. Across the brain, MD patches shows anatomical and physiological properties adapted to attentional integration.
.  Neurophysiology of putative MD regions shows adaptive coding of task-relevant information. Suiting attentional integration, many neurons show conjunctive coding (e.g., binding cognitive operations to their target objects).
.  In broad outline, these results suggest how distributed brain activity builds organized cognition.

Abstract: How does organized cognition arise from distributed brain activity? Recent analyses of fluid intelligence suggest a core process of cognitive focus and integration, organizing the components of a cognitive operation into the required computational structure. A cortical ‘multiple-demand’ (MD) system is closely linked to fluid intelligence, and recent imaging data define nine specific MD patches distributed across frontal, parietal, and occipitotemporal cortex. Wide cortical distribution, relative functional specialization, and strong connectivity suggest a basis for cognitive integration, matching electrophysiological evidence for binding of cognitive operations to their contents. Though still only in broad outline, these data suggest how distributed brain activity can build complex, organized cognition.

Keywords: intelligenceattentioncognitive controlbrain networksneural coding

Concluding Remarks and Future Directions

Many issues are raised by the integration account. Here we discuss two: the interface of short-term cognitive activity and long-term knowledge, and the nature of attentional capacity limitations.

As implied by our discussion of positive manifold, a core question is interface between on-line cognition and long-term knowledge. As in classical symbolic artificial intelligence (e.g., [97]), a complex problem is divided into simple parts on the basis of long-term knowledge of the structure of the world and relations within it. It is knowledge that tells us how travel to Japan can be divided into component steps, how a useful move can be made in proving a mathematical theorem, or where we should look in seeking a solution to a spatial puzzle. In the brain, knowledge that might shape current cognition is distributed across multiple brain systems. Semantic memory, for example, may be based around a proposed hub in the temporal pole [98], while episodic memory, spatial knowledge, and social knowledge are linked to distinct components of the default mode network [99]. To understand MD activity in constructing solutions to cognitive problems, we need to know how multiple aspects of knowledge feed into this process. Again, this is reminiscent of the widespread connectivity of MD regions (Figure 5) and our finding that multiple networks have representatives in the MD penumbra.

In classical artificial intelligence, problem solutions were often built up in an unlimited working memory, keeping track of a progressively more complex structure of goals and subgoals. For biological cognition this is not plausible; for goals such as travel to Japan or solving a scientific problem, only a small fraction can be represented in active neural firing at any one time, with the rest of the structure in long-term memory, ready for retrieval when required. At the same time, the current active focus of attention must remain bound to the long-term structure, so that, for example, a failure to progress to a goal by one route can trigger a search for an alternative. The issue is reminiscent of recent biological accounts of working memory, combining active neural firing with storage through short-term synaptic change [100,101]. It is presently unknown how the focus of attention in active cognition can be situated within a complex, long-term representation of the larger-scale problem.

A further open issue concerns the well-known capacity limitations of ‘attention’, reflected in difficulty carrying out several tasks at once [102,103]. Shared demands on MD activity could provide an obvious basis for such limits and, indeed, various authors have linked capacity limitations to the functions of frontal and parietal cortex [16,22,104,105]. Such proposals find support in neurophysiological studies, showing that, in frontal and parietal cortex, there is interference between representations of different visual stimuli [106], working memory items [107], or task components [86,108]. Further work is needed, however, to understand the physiological basis of this interference. In the visual system, capacity limits in representing multiple stimuli are thought to arise through a process of competition or divisive normalization [109., 110., 111.]. In such models, each stimulus attempts to drive the activity of a neuron to a particular value, appropriate to representing the properties of this stimulus; with multiple stimuli in the field, opposing forces bring activity to a compromise value, reducing the fidelity of representation for any one. Similar patterns can be seen in the visual responses of prefrontal neurons [112,113], raising the possibility that divisive normalization is a general principle in MD cortex. Recurrent neural networks have become popular as models of working memory and cognitive control (e.g., [114]), and in a recent model, divisive normalization is the basis for limited working memory capacity [115]. Further experimental work is needed to test whether divisive normalization models may be extended to the broader attentional limits of MD activity and cognitive control.

Of course, our account of cognitive integration leaves much unknown. That said, like an early map of the globe, it provides an outline sketch of how distributed brain activity can assemble complex cognition. This sketch, we suggest, provides the skeleton we need to guide future, more detailed physiological study (see Outstanding Questions).

Outstanding Questions

How do different MD regions interact? Across the extended MD system, we know little of the dynamics of information representation and exchange during task performance. The very different connectivities of MD regions imply separate functional contributions to cognitive integration, but in fMRI, the dominant picture is one of corecruitment. This picture may reflect the low temporal resolution of fMRI, rendering the method blind to high-speed information development and exchange. Elucidating how task-relevant information arises and is distributed across the network calls for simultaneous electrophysiological recordings in separate MD regions, either in experimental animals or patients implanted for intracranial recordings.

How does MD activity bind together coherent processing across multiple brain regions? Again, this calls for electrophysiological studies, addressing questions that include directional information flow at different stages of a cognitive operation, and the role of precise timing relations (e.g., oscillatory synchrony) across brain regions.

How are brief segments of cognition combined into complex goal–subgoal structures? For example, we know little of how sustained goal maintenance directs brain activity in pursuit of a series of subgoals. Especially for complex behavior, a critical question is interaction between immediate cognitive activity and long-term knowledge of goals, subgoals, and their relationships.

What is the role of prominent MD foci seen outside cerebral cortex, especially in caudate and cerebellum? Almost nothing is known of cortical-subcortical and cerebro-cerebellar interaction as cognitive operations are carried out. High-field imaging may bring the spatial resolution needed for studies of small subcortical structures.

Creative behaviors seem to yield survival & reproductive benefits; however, individuals often have to violate social norms; this deviance entails consequences detrimental for both survival and reproduction

The paradox of creativity. Eric Bonetto et al. New Ideas in Psychology, Volume 60, January 2021, 100820. https://doi.org/10.1016/j.newideapsych.2020.100820

Highlights
• Creative behaviors seem to yield survival and reproductive benefits.
• However, to be creative, individuals often have to violate social norms.
• This deviance entails consequences detrimental for both survival and reproduction.
• We propose to call this paradox the paradox of creativity.

Abstract: Creativity seems to yield survival and reproductive benefits. Creative behaviors allow individuals to solve problems in new and appropriate ways, and thus to promote their survival. They also facilitate bonding and constitute a signal of one's fitness, favoring attraction of mates. However, to be creative, individuals often have to violate social norms in order to promote change. So far, this deviance induced by creative behaviors had not been seen as an adaptive disadvantage. This deviance entails negative consequences as social exclusion or ostracism, which are detrimental for both survival (e.g., reduced access to resources within the group) and reproduction (reduced reproductive fitness). Thus, the adaptive benefits yielded by creativity have to be nuanced by these potential disadvantages. The paradox of creativity proposes a finer-grained vision of the adaptive reasons why creativity has been maintained within the human species, has evolved, and is collectively regulated. Research perspectives are also proposed.

Keywords: Evolutionary perspectiveCreativityParadox of creativity