A Multisite Preregistered Paradigmatic Test of the Ego-Depletion Effect.

We conducted a preregistered multilaboratory project (k = 36; N = 3,531) to assess the size and robustness of ego-depletion effects using a novel replication method, termed the paradigmatic replication approach. Each laboratory implemented one of two procedures that was intended to manipulate self-control and tested performance on a subsequent measure of self-control. Confirmatory tests found a nonsignificant result (d = 0.06). Confirmatory Bayesian meta-analyses using an informed-prior hypothesis (δ = 0.30, SD = 0.15) found that the data were 4 times more likely under the null than the alternative hypothesis. Hence, preregistered analyses did not find evidence for a depletion effect. Exploratory analyses on the full sample (i.e., ignoring exclusion criteria) found a statistically significant effect (d = 0.08); Bayesian analyses showed that the data were about equally likely under the null and informed-prior hypotheses. Exploratory moderator tests suggested that the depletion effect was larger for participants who reported more fatigue but was not moderated by trait self-control, willpower beliefs, or action orientation.

Vaccination with a live attenuated Acinetobacter baumannii deficient in thioredoxin provides protection against systemic Acinetobacter infection.

Multi-drug resistant Acinetobacter baumannii (MDR-Ab), an opportunistic pathogen associated with nosocomial and combat related infections, has a high mortality due to its virulence and limited treatment options. Deletion of the thioredoxin gene (TrxA) from a clinical isolate of MDR-Ab resulted in a 100-fold increase in 50% lethal dose (LD50) in a systemic challenge murine model. Thus, we investigated the potential use of this attenuated strain as a live vaccine against MDR-Ab. Mice were vaccinated by subcutaneous (s.c.) injection of 2×105 CFU of the ΔtrxA mutant, boosted 14days later with an equivalent inoculum, and then challenged 30days post-vaccination by i.p. injection with 10 LD50 of the wild type (WT) Ci79 strain. Efficacy of vaccination was evaluated by monitoring MDR-Ab specific antibody titers and cytokine production, observing pathology and organ burdens after WT challenge, and measuring levels of serum pentraxin-3, a molecular correlate of A. baumannii infection severity, before and after challenge. Mice vaccinated with ΔtrxA were fully protected against the lethal challenge of WT. However, minimal immunoglobulin class switching was observed with IgM predominating. Spleens harvested from vaccinated mice exhibited negligible levels of IL-4, IFN-γ and IL-17 production when stimulated with UV-inactivated WT Ci79. Importantly, tissues obtained from vaccinated mice displayed reduced pathology and organ burden compared to challenged non-vaccinated mice. Additionally, serum pentraxin-3 concentrations were not increased 24h after challenge in vaccinated mice, correlating with reduction of WT MDR-Ab infection in ΔtrxA immunized mice. Furthermore, passive immunization with ΔtrxA-immune sera provided protection against lethal systemic Ci79 challenge. Collectively, the defined live attenuated ΔtrxA strain is a vaccine candidate against emerging MDR Acinetobacter infection.

Differentiation of individual selves facilitates group-level benefits of ultrasociality.

Gowdy & Krall's target article complements our recent theorizing on group behavior. In our comment, we elucidate complementary aspects of the two theories and highlight the importance of differentiation of selves for human groups to reap the benefits of ultrasociality. We propose that achieving optimal group outcomes depends on the differentiation of individual selves.

Mental Health Professionals and Behavioral Interventions for Obesity: A Systematic Literature Review.

Adult obesity in the United States has risen to epidemic proportions, and mental health professionals must be called to action. The objectives of this article were to (a) synthesize outcomes of behavioral health interventions for adult obesity in recent meta-analyses and systematic reviews (MAs/SRs) as well as randomized controlled trials (RCTs) and further, (b) evaluate the role of mental health professionals in these behavioral health interventions. Articles were included if published in English between January 1, 2004, and May 1, 2014, in peer-reviewed journals examining behavioral health interventions for adults with obesity. Data were subsequently extracted and independently checked by two authors. Included MAs/SRs utilized motivational interviewing, financial incentives, multicomponent behavioral weight management programs, as well as dietary and lifestyle interventions. Behavioral health interventions in randomized controlled trials (RCTs) were discussed across 3 major intervention types (educational, modified caloric intake, cognitive-based). Regarding the 1st study objective, multiple positive primary (e.g., weight loss) and secondary outcomes (e.g., quality of life) were found in both MAs/SRs and RCTs. However, the majority of included studies made no mention of interventionist professional background and little inference could be made regarding the effects of professional background on behavioral health intervention outcomes for adults facing obesity; an important limitation and direction for future research. Future studies should assess the effects of interventionist profession in addition to primary and secondary outcomes for adults facing obesity. Implications for mental health professionals' educational curricula, assessment, and treatment strategies are discussed.

Are groups more or less than the sum of their members? The moderating role of individual identification.

This paper seeks to make a theoretical and empirical case for the importance of differentiated identities for group function. Research on groups has found that groups sometimes perform better and other times perform worse than the sum of their individual members. Differentiation of selves is a crucial moderator. We propose a heuristic framework that divides formation of work or task groups into two steps. One step emphasizes shared common identity and promotes emotional bonds. In the other step, which we emphasize, group members take increasingly differentiated roles that improve performance through specialization, moral responsibility, and efficiency. Pathologies of groups (e.g., social loafing, depletion of shared resources/commons dilemmas, failure to pool information, groupthink) are linked to submerging the individual self in the group. These pathologies are decreased when selves are differentiated, such as by individual rewards, individual competition, accountability, responsibility, and public identification. Differentiating individual selves contributes to many of the best outcomes of groups, such as with social facilitation, wisdom-of-crowds effects, and division of labor. Anonymous confidentiality may hamper differentiation by allowing people to blend into the group (so that selfish or lazy efforts are not punished), but it may also facilitate differentiation by enabling people to think and judge without pressure to conform. Acquiring a unique role within the group can promote belongingness by making oneself irreplaceable.

Differentiating selves facilitates group outcomes.

The target article proposed that differentiation of selves is a crucial moderator of group outcomes, such that differentiation of selves contributes to beneficial outcomes of groups while limiting undesirable outcomes. In this response, we aim to complement the target article by refining and expanding several aspects of the theory. We address our conceptualization of optimal group functioning, clarify the term differentiation of selves, comment on the two-step nature of our model, offer theoretical connections and extensions, and discuss applications and opportunities for future research.

The making of might-have-beens: effects of free will belief on counterfactual thinking.

Counterfactual thoughts are based on the assumption that one situation could result in multiple possible outcomes. This assumption underlies most theories of free will and contradicts deterministic views that there is only one possible outcome of any situation. Three studies tested the hypothesis that stronger belief in free will would lead to more counterfactual thinking. Experimental manipulations (Studies 1-2) and a measure (Studies 3-4) of belief in free will were linked to increased counterfactual thinking in response to autobiographical (Studies 1, 3, and 4) and hypothetical (Study 2) events. Belief in free will also predicted the kind of counterfactuals generated. Belief in free will was associated with an increase in the generation of self and upward counterfactuals, which have been shown to be particularly useful for learning. These findings fit the view that belief in free will is promoted by societies because it facilitates learning and culturally valued change.

Assailing the competition: sexual selection, proximate mating motives, and aggressive behavior in men.

Throughout history, men have tended to be more violent than women. Evolutionary theories suggest that this sex difference derives in part from their historically greater need to compete with other men over access to potential mates. In the current research, men and women (Experiment 1) or men only (Experiments 2 and 3) underwent a mating motive prime or control prime, and then performed a task designed to measure aggression toward a same-sex partner. The mating prime increased aggression among men, but not women (Experiment 1). Furthermore, mating-related increases in aggression were directed only toward men who were depicted as viable intrasexual rivals, including a dominant (vs. non-dominant) male partner (Experiment 2) and a man who was depicted as single (versus married) and looking for a mate (Experiment 3). This research provides a picture of male intrasexual aggression as highly selective and aimed strategically at asserting one's dominance over sexual rivals.

Ego depletion decreases trust in economic decision making.

Three experiments tested the effects of ego depletion on economic decision making. Participants completed a task either requiring self-control or not. Then participants learned about the trust game, in which senders are given an initial allocation of $10 to split between themselves and another person, the receiver. The receiver receives triple the amount given and can send any, all, or none of the tripled money back to the sender. Participants were assigned the role of the sender and decided how to split the initial allocation. Giving less money, and therefore not trusting the receiver, is the safe, less risky response. Participants who had exerted self-control and were depleted gave the receiver less money than those in the non-depletion condition (Experiment 1). This effect was replicated and moderated in two additional experiments. Depletion again led to lower amounts given (less trust), but primarily among participants who were told they would never meet the receiver (Experiment 2) or who were given no information about how similar they were to the receiver (Experiment 3). Amounts given did not differ for depleted and non-depleted participants who either expected to meet the receiver (Experiment 2) or were led to believe that they were very similar to the receiver (Experiment 3). Decreased trust among depleted participants was strongest among neurotics. These results imply that self-control facilitates behavioral trust, especially when no other cues signal decreased social risk in trusting, such as if an actual or possible relationship with the receiver were suggested.

Individual identity and freedom of choice in the context of environmental and economic conditions.

Van de Vliert's findings fit nicely with our recent arguments implying that (1) differentiated selfhood is partly motivated by requirements of cultural groups, and (2) free will mainly exists within culture. Some cultural groups promote individual freedom, whereas others constrict it so as to maintain elites' power and privilege. Thus, freedom is, to a great extent, a creation of culture.

Cooperation and fairness depend on self-regulation.

Any evolved disposition for fairness and cooperation would not replace but merely compete with selfish and other antisocial impulses. Therefore, we propose that human cooperation and fairness depend on self-regulation. Evidence shows reductions in fairness and other prosocial tendencies when self-regulation fails.

Sex begets violence: mating motives, social dominance, and physical aggression in men.

There are sizable gender differences in aggressive behavior, with men displaying a much higher propensity for violence than women. Evolutionary theories suggest that men's more violent nature derives in part from their historically greater need to compete over access to potential mates. The current research investigates this link between mating and male violence and provides rigorous experimental evidence that mating motives cause men to behave violently toward other men. In these studies, men and women were primed with a mating motive and then performed a noise-blast aggression task. Being primed with mating led men, but not women, to deliver more painful blasts of white noise to a same-sex partner (but not an opposite-sex partner). This effect was particularly pronounced among men with an unrestricted sociosexual orientation, for whom competition over access to new mates is an especially relevant concern. Findings also suggest that mating-induced male violence is motivated by a desire to assert one's dominance over other men: when men were given feedback that they had won a competition with their partner (and thus had achieved dominance through nonaggressive means), the effect of the mating prime on aggression was eliminated. These findings provide insight into the motivational roots of male aggression and illustrate the value of testing theories from evolutionary biology with rigorous experimental methods.