Self-control relies on glucose as a limited energy source: willpower is more than a metaphor

Testing the validity of the attention control video: An eye-tracking approach of the ego depletion effect

The attention control video has been frequently applied to test the ego depletion effect. However, its validity has never been tested, a shortcoming we address in this preregistered study. In the first task, self-control strength was temporarily depleted in the depletion condition (n = 56) but remained intact in the control condition (n = 56). The attention control video served as the secondary task, and we assumed that the depletion condition would perform significantly worse compared to the control condition. Attention regulation was measured with an eye-tracking device. The results revealed that the gaze behavior in the two conditions differed statistically significantly; however, the actual difference was small, indicating that the attention control video may not be an optimal measure of self-control.

Self-Leadership: A Paradoxical Core of Organizational Behavior

This review focuses on the paradoxical concept of self-leadership—defined as a comprehensive self-influence process capturing how individuals motivate themselves to complete work that is naturally motivating or work that must be done but is not naturally motivating—as a fundamental process that challenges many traditional assumptions in organizational psychology and organizational behavior. We first present a historical review that traces the roots of self-leadership to early psychological theory and research. We next briefly summarize research related to self-leadership at both the individual and team levels of analysis. We then discuss four paradoxes associated with self-leadership: the paradox of self-leadership depletion and strengthening, the paradox of self-leadership through collaboration, the paradox of me-but-not-you self-leadership, and the paradox of needing self-leadership to improve self-leadership. We conclude with guidelines for future research and practice.

Reported Self-control is not Meaningfully Associated with Inhibition-related Executive Function: A Bayesian Analysis

Self-control is assessed using a remarkable array of measures. In a series of five data-sets (overall N = 2,641) and a mini meta-analysis, we explored the association between canonical operationalisations of self-control: The Self-Control Scale and two measures of inhibition-related executive functioning (the Stroop and Flanker paradigms). Overall, Bayesian correlational analyses suggested little-to-no relationship between self-reported self-control and performance on the Stroop and Flanker tasks. The Bayesian meta-analytical summary of all five data-sets further favoured a null relationship between both types of measurement. These results suggest that the field’s most widely used measure of self-reported self-control is uncorrelated with two of the most widely adopted executive functioning measures of self-control. Consequently, theoretical and practical conclusions drawn using one measure (e.g., the Self-Control Scale) cannot be generalised to findings using the other (e.g., the Stroop task). The lack of empirical correlation between measures of self-control do not invalidate either measure, but instead suggest that treatments of the construct of self-control need to pay greater attention to convergent validity among the many measures used to operationalize self-control.

Bridging Exercise Science, Cognitive Psychology, and Medical Practice: Is "Cognitive Fatigue" a Remake of "The Emperor's New Clothes"?

Fatigue is such a multifaceted construct it has sprouted specific research fields and experts in domains as different as exercise physiology, cognitive psychology, human factors and engineering, and medical practice. It lacks a consensus definition: it is an experimental concept, a symptom, a risk, a cause (e.g., of performance decrement) and a consequence (e.g., of sleep deprivation). This fragmentation of knowledge leads to slower dissemination of novel insights, and thus to a poorer research. Indeed, what may seem as a novel result in one field, may very well be old news in another, hence leading to this "innovation" being a scientific equivalent to the emperor's new clothes. The current paper aims to describe the common denominator in the different areas of expertise where fatigue is investigated. Indeed, rather than focusing on the differences in semantics and conceptualization, we hope that identifying common concepts may be inductive of easier multidisciplinary research. Considering the vastness of fatigue research in all areas identified as relevant-cognitive science, exercise physiology, and medical practice, this analysis has not the ambition to be an exhaustive review in all domains. We have reviewed the fatigue concepts and research in these areas and report the ones that are used to describe the proposed common model to be further investigated. The most promising common feature to cognitive science, exercise physiology and clinical practice is the notion of "perceived effort." This allows to account for interindividual differences, as well as for the situational variations in fatigue. It is applicable to both mental and physical constructs. It integrates motivational and emotional dimensions. It overcomes current polemics in various research fields, and it does not draw on any semantic ambiguity. We thus suggest a new model of fatigue and performance, whether this performance is mental or physical; and whether it is in a clinical range or relates to optimal functioning.

Mental labour

Mental effort is an elementary notion in our folk psychology and a familiar fixture in everyday introspective experience. However, as an object of scientific study, mental effort has remained rather elusive. Cognitive psychology has provided some tools for understanding how effort impacts performance, by linking effort with cognitive control function. What has remained less clear are the principles that govern the allocation of mental effort. Under what circumstances do people choose to invest mental effort, and when do they decline to do so? And what regulates the intensity of mental effort when it is applied? In new and promising work, these questions are being approached with the tools of behavioural economics. Though still in its infancy, this economic approach to mental effort research has already uncovered important aspects of effort-based decision-making, and points clearly to future lines of inquiry, including some intriguing opportunities presented by recent artificial intelligence research.

Development of a Within-Subject, Repeated-Measures Ego-Depletion Paradigm

Abstract. Ego depletion is under scrutiny for low replicability, possibly reflecting the limited statistical power available in between-subject designs. In response, we created a within-subject, repeated-measures ego-depletion paradigm that repeatedly alternated depletion and recovery manipulations. Each manipulation was followed by measuring subjective fatigue, mood, and self-control performance. Across 12 studies (N = 754), participants reliably reported having lower energy and mood after depleting manipulations compared to after recovery manipulations. Depletion manipulations did not consistently affect behavioral self-control, although the depletion effect was meta-analytically significant (d = .045). Furthermore, unintended fatigue and practice effects occurred over the course of the paradigm, systematically interfering with the intended depletion effects. We recommend that depletion research takes advantage of within-subject designs across multiple sessions to avoid spillover effects between measurements.

Ego-depletion increases selfish decision making, but may also increase self-conflict and regret about those decisions

The effect of ego-depletion on self-control conflict identification is the subject of ongoing debate with only limited and indirect empirical assessment. The present research used behavioral and self-report measures to test if ego-depletion affects self-control conflict identification across two studies: in an economic social dilemma game and a probe reaction task. In the social dilemma game, ego-depleted participants acted more selfishly, but also reported feeling more conflicted about their decisions and were more likely to go back and change choices they had made earlier in the game. These results replicated and extended earlier findings on ego-depletion and prosocial behavior. Study Two tested the effect of ego-depletion on self-control conflict identification using a probe recognition task designed to measure goal conflict accessibility, but found no significant effects of ego-depletion.

Psychological functioning in Parkinson's disease post-deep brain stimulation: Self-regulation and executive functioning

Parkinson's disease (PD) is a neurodegenerative disorder involving the basal ganglia, resulting in motor and extra-motor deficits. These extra-motor deficits may be reflective of a self-regulatory deficit impacting patients' ability to regulate cognitive processes, thoughts, behaviors, and emotions. There is a need to further examine the prevalence and range of self-regulation (SR) and executive functioning (EF) impairments in PD. This study sought to do so in a sample of patients with PD (N = 31) who underwent deep brain stimulation (DBS) surgery for motor symptom treatment. Patients completed measures indicative of SR and EF including neurocognitive tests, heart rate variability (HRV), and self-report questionnaires to examine these constructs in PD. The highest prevalence of impairments were observed for total impulse control disorder (ICD) symptoms (74%), depressive symptoms (48%), verbal fluency (phonemic: 39%; semantic: 36%), mental flexibility (32%), and self-reported SR impairments (Metacognition: 32%; Behavioral Regulation: 29%). Correlations among theoretically related constructs (i.e., SR, EF) were modest and variable; challenging the idea that SR is a unitary construct for which different domains depend on a common resource. In patients with PD post-DBS, higher resting HRV, thought to be indicative of better autonomic functioning, was linked to better EF in some instances but not others and not significantly associated with self-report SR. Overall, patients with PD exhibit various extra-motor deficits, ranging from subtle to severe. Health care professionals working with patients with PD should recognize the presence of extra-motor deficits, particularly ICDs, and obstacles that might arise from such impairments in patients' daily lives.

Vagal Tank Theory: The Three Rs of Cardiac Vagal Control Functioning - Resting, Reactivity, and Recovery

The aim of this paper is to set the stage for the vagal tank theory, showcasing a functional resource account for self-regulation. The vagal tank theory, building on neurophysiological, cognitive and social psychology approaches, will introduce a physiological indicator for self-regulation that has mainly been ignored from cognitive and social psychology, cardiac vagal control (also referred to as cardiac vagal activity). Cardiac vagal control reflects the contribution of the vagus nerve, the main nerve of the parasympathetic nervous system, to cardiac regulation. We propose cardiac vagal control to be an indicator of how efficiently self-regulatory resources are mobilized and used. Three systematic levels of cardiac vagal control analysis are suggested: resting, reactivity, and recovery. Based on this physiological indicator we derive the metaphor of the vagal tank, which can get depleted and replenished. Overall, the vagal tank theory will enable to integrate previous findings from different disciplines and to stimulate new research questions, predictions, and designs regarding self-regulation.

Mental Work Requires Physical Energy: Self-Control Is Neither Exception nor Exceptional

The brain’s reliance on glucose as a primary fuel source is well established, but psychological models of cognitive processing that take energy supply into account remain uncommon. One exception is research on self-control depletion, where debate continues over a limited-resource model. This model argues that a transient reduction in self-control after the exertion of prior self-control is caused by the depletion of brain glucose, and that self-control processes are special, perhaps unique, in this regard. This model has been argued to be physiologically implausible in several recent reviews. This paper attempts to correct some inaccuracies that have occurred during debate over the physiological plausibility of this model. We contend that not only is such limitation of cognition by constraints on glucose supply plausible, it is well established in the neuroscience literature across several cognitive domains. Conversely, we argue that there is no evidence that self-control is special in regard to its metabolic cost. Mental processes require physical energy, and the body is limited in its ability to supply the brain with sufficient energy to fuel mental processes. This article reviews current findings in brain metabolism and seeks to resolve the current conflict in the field regarding the physiological plausibility of the self-control glucose-depletion hypothesis.

Mindset switching increases the use of 'want-based' over 'should-based' behaviors

This study examines the consequences of mindset switching on behavioral choices in want/should conflicts. Building on the insights of the ego depletion literature, we propose that mindset switching depletes individuals’ self-control resources and therefore prompts the choice of want behavior, which provides immediate pleasure, over should behavior, which provides long-term utility. Four laboratory experiments with university students that stimulated individuals to switch mindsets were conducted to test our hypotheses. Experiment 1 demonstrated that switching between individualist and collectivist mindsets increased the subjects’ tendency to prefer popular magazines over scientific journals. Experiment 2 replicated the results by testing the relationship between an abstract/concrete mindset-switching task and want/should online behavioral choices. The mediating effect of ego depletion was also supported. Experiment 3 retested the main effect of language-switching on reading choices, and the mediating effect of ego-depletion. Experiment 3 also tested the moderating effect of the Need for Cognition, and eliminated the alternative explanation of cognitive fatigue. In Experiment 4, actual food choices were used as the direct measure of want/should behaviors to test the robustness of our findings. The results consistently supported our hypotheses that mindset switching has significant effects on behavioral choices in terms of overindulgence, such as increasing want behavior and thus foregoing should behavior.

A Simple, Principled Approach to Combining Evidence From Meta-Analysis and High-Quality Replications

Recent discussions of the influence of publication bias and questionable research practices on psychological science have increased researchers’ interest in both bias-correcting meta-analytic techniques and preregistered replication. Both approaches have their strengths: For example, meta-analyses can quantitatively characterize the full body of work done in the field of interest, and preregistered replications can be immune to bias. Both approaches also have clear weaknesses: Decisions about which meta-analytic estimates to interpret tend to be controversial, and replications can be discounted for failing to address important methodological heterogeneity. Using the experimental literature on ego depletion as a case study, we illustrate a principled approach to combining information from meta-analysis with information from subsequently conducted high-quality replications. This approach (a) compels researchers to explicate their beliefs in meta-analytic conclusions (and also, when controversy arises, to defend the basis for those beliefs), (b) encourages consideration of practical significance, and (c) facilitates the process of planning replications by specifying the sample sizes necessary to have a reasonable chance of changing the minds of other researchers.

Why Is Working Memory Performance Unstable? A Review of 21 Factors

In this paper, we systematically reviewed twenty-one factors that have been shown to either vary with or influence performance on working memory (WM) tasks. Specifically, we review previous work on the influence of intelligence, gender, age, personality, mental illnesses/medical conditions, dieting, craving, stress/anxiety, emotion/motivation, stereotype threat, temperature, mindfulness training, practice, bilingualism, musical training, altitude/hypoxia, sleep, exercise, diet, psychoactive substances, and brain stimulation on WM performance. In addition to a review of the literature, we suggest several frameworks for classifying these factors, identify shared mechanisms between several variables, and suggest areas requiring further investigation. This review critically examines the breadth of research investigating WM while synthesizing the results across related subfields in psychology.

Effects of blood glucose on delay discounting, food intake and counterregulation in lean and obese men

BACKGROUND

Delay discounting as a measure of impulsivity has been shown to be higher in obesity with an association of increased food intake. Moreover, obese humans showed a higher wanting for high-calorie food than lean men when blood glucose concentrations were low. First studies linking blood glucose levels to delay discounting yielded mixed results. We hypothesized that obese people - in comparison to lean men - have a relative lack of energy, especially when blood glucose levels are low, that results in higher levels of delay discounting, food intake and hormonal counterregulation.

METHODS

We investigated 20 lean and 20 obese healthy young men in a single-blind balanced cross-over design. With a standardized glucose clamp technique, subjects underwent a hypoglycemic state in one condition and a euglycemic state in the control condition. Regularly, blood was sampled for assessment of hormonal status, and questionnaires were filled out to assess delay discounting and symptom awareness. After normalizing blood glucose concentrations, subjects were free to eat from a standardized test buffet, followed by a snack test.

RESULTS

Delay discounting was higher in obese than in lean men throughout experiments (p < 0.03). However, we did not observe significant discounting differences between glucose conditions (p > 0.1). Furthermore, the discounting performance did not correlate with food intake from the test buffet or snack test (p > 0.3). As a response to hypoglycemia, hormonal counterregulation was pronounced in both weight groups (p < 0.03), but responses of ACTH, norepinephrine and glucagon were stronger in obese compared to lean men (p < 0.03). Also, intake from the high-calorie buffet after hypoglycemia compared to euglycemia was higher in obese subjects (p < 0.02) but comparable in lean men (p > 0.5).

CONCLUSIONS

Our data suggest that augmented delay discounting is a robust feature in obesity that is not linked to glucose levels or actual food intake. With our systematically controlled approach, combining performance in delay discounting with regard to distinct blood glucose levels, different weight groups, counterregulatory behavior and food intake, our results imply that delay discounting is not susceptible to fluctuations of blood glucose and do not support the assumption that a low body's energy content leads to increased impulsivity. Further replications including women and larger sample sizes are needed to corroborate our data.

Fairness, fast and slow: A review of dual process models of fairness

Fairness, the notion that people deserve or have rights to certain resources or kinds of treatment, is a fundamental dimension of moral cognition. Drawing on recent evidence from economics, psychology, and neuroscience, we ask whether self-interest is always intuitive, requiring self-control to override with reasoning-based fairness concerns, or whether fairness itself can be intuitive. While we find strong support for rejecting the notion that self-interest is always intuitive, the literature has reached conflicting conclusions about the neurocognitive systems underpinning fairness. We propose that this disagreement can largely be resolved in light of an extended Social Heuristics Hypothesis. Divergent findings may be attributed to the interpretation of behavioral effects of ego depletion or neurostimulation, reverse inference from brain activity to the underlying psychological process, and insensitivity to social context and inter-individual differences. To better dissect the neurobiological basis of fairness, we outline how future research should embrace cross-disciplinary methods that combine psychological manipulations with neuroimaging, and that can probe inter-individual, and cultural heterogeneities.

Efficiency: an underlying principle of learning?

Learning is essential. It allows animals to change circumstances, deal with new situations and adapt to environments. Here, we argue that learning, at behavioral and neural levels, involves efficiency, reflected in metabolic cost reductions. Behaviourally, although multiple solutions to a novel problem may be available, all solutions are not learnt – it is too costly. Furthermore, once a strategy has been selected, it is reinforced producing an efficiency that leads to a maximisation of performance and metabolic cost reductions. Learning can be represented in the brain through many mechanisms; however, if learning is truly efficient, then, all such mechanisms should also be accompanied by a reduction in measurable metabolic costs. By thinking about learning in terms of efficiency, not simply as a descriptive term but rather in terms of metabolic costs, it allows learning to be examined more carefully and provides predictions that can be easily tested (and indeed refuted).

The influence of stress responses on surgical performance and outcomes: Literature review and the development of the surgical stress effects (SSE) framework

BACKGROUND

Surgical adverse events persist despite several decades of system-based quality improvement efforts, suggesting the need for alternative strategies. Qualitative studies suggest stress-induced negative intraoperative interpersonal dynamics might contribute to performance errors and undesirable patient outcomes. Understanding the impact of intraoperative stressors may be critical to reducing adverse events and improving outcomes.

DATA SOURCES

We searched MEDLINE, psycINFO, EMBASE, Business Source Premier, and CINAHL databases (1996-2016) to assess the relationship between negative (emotional and behavioral) responses to acute intraoperative stressors and provider performance or patient surgical outcomes.

RESULTS/CONCLUSIONS

Drawing on theory and evidence from reviewed studies, we present the Surgical Stress Effects (SSE) framework. This illustrates how emotional and behavioral responses to stressors can influence individual surgical provider (e.g. surgeon, nurse) performance, team performance, and patient outcomes. It also demonstrates how uncompensated intraoperative threats and errors can lead to adverse events, highlighting evidence gaps for future research efforts.

The Effects of Carbohydrates, in Isolation and Combined with Caffeine, on Cognitive Performance and Mood-Current Evidence and Future Directions

This review examines the effects of carbohydrates, delivered individually and in combination with caffeine, on a range of cognitive domains and subjective mood. There is evidence for beneficial effects of glucose at a dose of 25 g on episodic memory, but exploration of dose effects has not been systematic and the effects on other cognitive domains is not known. Factors contributing to the differential sensitivity to glucose facilitation include age, task difficulty/demand, task domain, and glucoregulatory control. There is modest evidence to suggest modulating glycemic response may impact cognitive function. The evidence presented in this review identifies dose ranges of glucose and caffeine which improve cognition, but fails to find convincing consistent synergistic effects of combining caffeine and glucose. Whilst combining glucose and caffeine has been shown to facilitate cognitive performance and mood compared to placebo or glucose alone, the relative contribution of caffeine and glucose to the observed effects is difficult to ascertain, due to the paucity of studies that have appropriately compared the effects of these ingredients combined and in isolation. This review identifies a number of methodological challenges which need to be considered in the design of future hypothesis driven research in this area.

Cognitive fatigue effects on physical performance: A systematic review and meta-analysis

Recent research has examined the effect that undertaking a cognitively fatiguing task for ≤90 min has on subsequent physical performance. Cognitive fatigue is claimed to affect subsequent physical performance by inducing energy depletion in the brain, depletion of brain catecholamine neurotransmitters or changes in motivation. Observation of the psychophysiology and neurochemistry literature questions the ability of 90 min' cognitive activity to deplete energy or catecholamine resources. The purpose of this study, therefore, was to examine the evidence for cognitive fatigue having an effect on subsequent physical performance. A systematic, meta-analytic review was undertaken. We found a small but significant pooled effect size based on comparison between physical performance post-cognitive fatigue compared to post-control (g = -0.27, SE = -0.12, 95% CI -0.49 to -0.04, Z(10) = -2.283, p < 0.05). However, the results were not heterogenous (Q(10) = 2.789, p > 0.10, Τ² < 0.001), suggesting that the pooled effect size does not amount to a real effect and differences are due to random error. No publication bias was evident (Kendall's τ = -0.07, p > 0.05). Thus, the results are somewhat contradictory. The pooled effect size shows a small but significant negative effect of cognitive fatigue, however tests of heterogeneity show that the results are due to random error. Future research should use neuroscientific tests to ensure that cognitive fatigue has been achieved.

Influence of blood glucose level on the prognosis of patients with diabetes mellitus complicated with ischemic stroke

We carried out this meta-analysis for the aim of exploring the influence of diabetes mellitus (DM) on the prognosis of patients with ischemic stroke. Relevant studies were identified using computerized databases supplemented with manual search strategies. The included studies were strictly followed the inclusion and exclusion criteria. Case-control studies which related to the influence of DM on the prognosis of patients with ischemic stroke were selected. Statistical analyses were implemented with the STATA version 12.0 statistical software. Our current meta-analysis initially retrieved 253 studies (227 in Chinese and 26 in English), 13 studies (6 in English and 7 in Chinese) were eventually incorporated in this meta-analysis. These 13 case-control studies included 8463 patients altogether (3249 patients with DM complicated with ischemic stroke and 5214 patients with ischemic stroke). The results of this meta-analysis manifested that there was a significant difference of the blood glucose level at 48 h after stroke between patients with DM complicated with ischemic stroke and patients with ischemic stroke (standard mean difference [SMD] =1.27, 95% confidence interval [CI] =0.02–2.51, P = 0.047); however, the effectiveness, fatality, and the National Institutes of Health Stroke Scale (NIHSS) score in patients with DM complicated with ischemic stroke, and patients with ischemic stroke had no significant difference (effectiveness: risk ratio [RR] = 0.88, 95% CI = 0.75–1.03, P = 0.121; fatality: RR = 1.29, 95% CI = 0.97–1.71, P = 0.081; NIHSS score: SMD = −0.14, 95% CI = −1.56-1.28, P = 0.849). The current evidence suggests that there is statistical difference of the blood glucose level at 48 h after stroke between patients with DM complicated with ischemic stroke and patients with ischemic stroke, but there is no statistical difference of prognostic indicators between patients in two groups. Thus, our study provides certain clinical value.

On Finding the Source of Human Energy: The Influence of Famous Quotations on Willpower

Positive psychology focuses on aspects that human beings can improve, thereby enhancing their growth and happiness. One of these aspects is willpower, a quality that has been demonstrated to have various benefits on people, as widely shown in the literature. As a result, a growing body of research is attempting to establish the conditions under which an individual’s willpower can be increased. This work attempts to confirm whether the famous quotations that people often use to inspire or motivate themselves can have a real effect on willpower. Two experiments were conducted assigning randomly subjects to a group and priming them with famous quotations, and afterwards comparing their performance in a willpower task with a control group. The second experiment added a willpower depletion task before priming. As a result, primed subjects endured the willpower task significantly more time than control group, demonstrating that famous quotations related to willpower help to increase this capacity and to counteract the effect of willpower depletion.

Self-regulation resources and physical activity participation among adults with type 2 diabetes

Physical activity plays a crucial role in the prevention and treatment of type 2 diabetes. Therefore, it is important to understand why so few adults with type 2 diabetes regularly engage in physical activity. The role of self-regulation in the context of health-related behavior adherence, especially in terms of physical activity engagement and adherence, has largely been reviewed based on the strength energy model. Building on this line of research, the aim of this theoretical work was to highlight how self-regulation and ego depletion can influence the lower rate of physical activity participation among adults with type 2 diabetes, compared to adults from the general population.

21st century neurobehavioral theories of decision making in addiction: Review and evaluation

This review critically examines neurobehavioral theoretical developments in decision making in addiction in the 21st century. We specifically compare each theory reviewed to seven benchmarks of theoretical robustness, based on their ability to address: why some commodities are addictive; developmental trends in addiction; addiction-related anhedonia; self-defeating patterns of behavior in addiction; why addiction co-occurs with other unhealthy behaviors; and, finally, means for the repair of addiction. We have included only self-contained theories or hypotheses which have been developed or extended in the 21st century to address decision making in addiction. We thus review seven distinct theories of decision making in addiction: learning theories, incentive-sensitization theory, dopamine imbalance and systems models, opponent process theory, strength models of self-control failure, the competing neurobehavioral decision systems theory, and the triadic systems theory of addiction. Finally, we have directly compared the performance of each of these theories based on the aforementioned benchmarks, and highlighted key points at which several theories have coalesced.

Cooperation and the evolution of hunter-gatherer storytelling

Storytelling is a human universal. From gathering around the camp-fire telling tales of ancestors to watching the latest television box-set, humans are inveterate producers and consumers of stories. Despite its ubiquity, little attention has been given to understanding the function and evolution of storytelling. Here we explore the impact of storytelling on hunter-gatherer cooperative behaviour and the individual-level fitness benefits to being a skilled storyteller. Stories told by the Agta, a Filipino hunter-gatherer population, convey messages relevant to coordinating behaviour in a foraging ecology, such as cooperation, sex equality and egalitarianism. These themes are present in narratives from other foraging societies. We also show that the presence of good storytellers is associated with increased cooperation. In return, skilled storytellers are preferred social partners and have greater reproductive success, providing a pathway by which group-beneficial behaviours, such as storytelling, can evolve via individual-level selection. We conclude that one of the adaptive functions of storytelling among hunter gatherers may be to organise cooperation.

Storytelling entails costs in terms of time and effort, yet it is a ubiquitous feature of human society. Here, Smith et al. show benefits of storytelling in Agta hunter-gatherer communities, as storytellers have higher reproductive success and storytelling is associated with higher cooperation in the group.

Diet quality and bullying among a cross-national sample of youth

Bullying perpetration and victimization have been linked to a number of high-risk health behaviors, including involvement in sedentary activities and sleep deprivation. Even so, the link between diet quality and bullying is generally overlooked. The present study examines the associations between diet quality, bully perpetration, and bully victimization in a cross-national sample of adolescents. Data come from the Health Behaviors of School Children (HBSC) survey, 2005/2006 (N=142,828-143,425). Youths from 41 countries/regions in North America and Europe reported features of their social context, various health behaviors, and their involvement in bullying. Approximately 11% of youth in the sample bully other youths at least 2-3 times a month, whereas 13% of youth are bullied by other youths at least 2-3 times a month. Logistic regression analyses revealed that youths with low quality diets incurred a 123% increase in the odds of attaining bully status, relative to youths with high quality diets. No such association was detected between diet quality and victim status. Results also suggest that the association between low diet quality and bully perpetration is significantly more pronounced in very developed nations (relative to developed nations). Dietary behaviors may be an important point of intervention in the effort to minimize the prevalence of bullying among youths, particularly in very developed nations. Scholars should seek to build upon the current study by exploring the mechanisms (e.g., low self-control) that might explain the association between diet quality and bullying.

Effects of Mental Fatigue on Physical Endurance Performance and Muscle Activation Are Attenuated by Monetary Incentives

Physical performance is impaired following cognitive control exertion. Incentives can ameliorate adverse carryover effects of cognitive control exertion but have not been investigated for physical endurance. This study examined the effect of monetary incentives on physical performance and muscle activation following exposure to a mentally fatiguing, cognitive control task. Participants (N = 82) performed two isometric endurance handgrip trials separated by a 12-min cognitive control manipulation using a 2 (high cognitive control [HCC]/low cognitive control [LCC]) × 2 (incentive/no incentive) design. Mental fatigue was significantly higher in the HCC conditions. Performance decreased in the HCC/no incentive condition but was unaffected in the HCC/incentive condition, which did not differ from the low cognitive control conditions. Electromyography data revealed increased muscle activation in the HCC/no incentive condition, which was also attenuated in the HCC/incentive condition. Findings show that incentives counteract the negative effects of HCC on physical endurance and alter central drive to motor units.

Evaluación de una intervención para la mejora de las competencias de regulación interpersonal del afecto y el bienestar laboral en una muestra de operadores penitenciarios del Uruguay

La utilización de estrategias controladas para la regulación interpersonal (ECRI) del afecto de la población reclusa puede afectar al bienestar de los operadores de prisiones. Según estudios previos, las ECRIs orientadas a mejorar el afecto de otros incrementan el bienestar del agente que las ejecuta. Al contrario, las ECRIs orientadas a empeorar el afecto deterioran su bienestar. Estos resultados se explican, según el Modelo de Fuerza de la Autorregulación y el Modelo de Conservación de Recursos, a partir del equilibrio entre el consumo de recursos de auto-regulación ligados a la ECRIs y los efectos diferenciales de dichas estrategias sobre los procesos de recuperación de este tipo de recursos. El presente estudio, basado en un diseño cuasi-experimenta, evalúa la eficacia de un programa de formación en ECRI orientado a la mejora del bienestar. Los resultados reflejan un mayor nivel de bienestar y un menor nivel de ECRIS orientadas al empeoramiento en los participantes en la formación (N= 21), cuando se comparan el un grupo de control (N= 18). No se encontraron diferencias significativas para las ECRIs de mejora. Los análisis de regresión jerárquica muestran que los cambios en las ECRIS de empeoramiento predicen negativamente los cambios en el nivel de bienestar.

Does Short-Term Hunger Increase Trust and Trustworthiness in a High Trust Society?

We build on the social heuristics hypothesis, the literature on the glucose model of self-control, and recent challenges on these hypotheses to investigate whether individuals exhibit a change in degree of trust and reciprocation after consumption of a meal. We induce short-term manipulation of hunger followed by the trust game and a decision on whether to leave personal belongings in an unlocked and unsupervised room. Our results are inconclusive. While, we report hungry individuals trusting and reciprocating more than those who have just consumed a meal in a high trust society, we fail to reject the null with small number of observations (N = 101) and experimental sessions (N = 8). In addition, we find no evidence of short-term hunger having an impact on charitable giving or decisions in public good game.

Depletion, moral identity, and unethical behavior: Why people behave unethically after self-control exertion

Self-control enables people to resist short-term temptations in the service of long-term goals. Previous exertion of self-control leads to a state of ego depletion. Three studies demonstrated that ego depletion leads to a high level of unethical behavior. These studies also hypothesized and confirmed that depleted individuals behave unethically because of low moral identity. Study 1 found that depleted participants were more likely to over-report their performance than non-depleted participants. Study 2 revealed that depletion reduced people's moral identity, which in turn increased their propensity to engage in unethical behavior. Study 3 proved that priming moral identity eliminated the effect of depletion on cheating. Findings suggest that reduced moral identity accounts for the effect of self-control depletion on unethical behavior.

Cognitive effects of a 30-min aerobic exercise bout on adults with overweight/obesity and type 2 diabetes

BACKGROUND

Several studies document reliable brain health benefits of acute exercise bouts. However, no prior studies have explored such effects among those living with co-morbid overweight/obesity and type 2 diabetes (T2DM), both of which are conditions associated with cognitive performance decrements.

PURPOSE

To examine the impact of a 30-min bout of moderate-intensity aerobic exercise on executive function among adults with overweight/obesity and T2DM, employing a widely used experimental paradigm.

METHODS

Thirty adults with overweight/obesity and T2DM were randomly assigned to moderate (30% maximal heart rate reserve) and minimal (r.p.m. 30-50; work load 5) intensity aerobic exercise. Pre-exercise to post-exercise changes in Stroop interference and Go/No-Go scores were compared across conditions.

RESULTS

Primary analyses revealed no overall effect of exercise condition on changes in Stroop or Go/No-Go performance. Post-hoc moderation analyses indicated that Stroop interference scores were reduced, following moderate exercise among female participants and among those who were more physically active.

CONCLUSION

The current study revealed no reliable benefit of acute aerobic exercise for overweight and obese individuals living with T2DM overall. There may be limited benefits for women and more and active subgroups, but the precise nature of such benefits remains unclear.