Prestige and dominance are thought to be two evolutionarily distinct routes to gaining status and influence in human social hierarchies. Prestige is attained by having specialist knowledge or skills ...that others wish to learn, whereas dominant individuals use threat or fear to gain influence over others. Previous studies with groups of unacquainted students have found prestige and dominance to be two independent avenues of gaining influence within groups. We tested whether this result extends to naturally occurring social groups. We ran an experiment with 30 groups of people from Cornwall, UK (
= 150). Participants answered general knowledge questions individually and as a group, and subsequently nominated a representative to answer bonus questions on behalf of the team. Participants then anonymously rated all other team-mates on scales of prestige, dominance, likeability and influence on the task. Using a model comparison approach with Bayesian multi-level models, we found that prestige and dominance ratings were predicted by influence ratings on the task, replicating previous studies. However, prestige and dominance ratings did not predict who was nominated as team representative. Instead, participants nominated team members with the highest individual quiz scores, despite this information being unavailable to them. Interestingly, team members who were initially rated as being high status in the group, such as a team captain or group administrator, had higher ratings of both dominance and prestige than other group members. In contrast, those who were initially rated as someone from whom others would like to learn had higher prestige, but not higher dominance, supporting the claim that prestige reflects social learning opportunities. Our results suggest that prestige and dominance hierarchies do exist in naturally occurring social groups, but that these hierarchies may be more domain-specific and less flexible than we anticipated.
Analogies, broadly defined, map novel concepts onto familiar concepts, making them essential for perception, reasoning, and communication. We argue that analogy-building served a critical role in the ...evolution of cumulative culture by allowing humans to learn and transmit complex behavioural sequences that would otherwise be too cognitively demanding or opaque to acquire. The emergence of a protolanguage consisting of simple labels would have provided early humans with the cognitive tools to build explicit analogies and to communicate them to others. This focus on analogy-building can shed new light on the coevolution of cognition and culture and addresses recent calls for better integration of the field of cultural evolution with cognitive science.
Analogies map novel concepts onto familiar concepts, aiding the learning and transmission of novel information.Analogies have been studied in cognitive science for years; here we connect this literature with the theory of cultural evolution.Cultural evolution provides a framework for understanding how human culture changes over time, but has been criticised for a lack of emphasis on the cognitive and communicative mechanisms that support cultural transmission.We suggest that a simple protolanguage consisting of labels would have catalysed cumulative cultural evolution by allowing analogy-building to proliferate.Labelling a novel object or action in relation to a familiar one would be particularly helpful for the transmission of cognitively opaque sequences, on which much of human cumulative culture relies.
Prestige-biased social learning occurs when individuals preferentially learn from others who are highly respected, admired, copied, or attended to in their group. This form of social learning is ...argued to reflect novel forms of social hierarchy in human societies, and, by providing an efficient short-cut to acquiring adaptive information, underpin the cumulative cultural evolution that has contributed to our species' ecological success. Despite these potentially important consequences, little empirical work to date has tested the basic predictions of prestige-biased social learning. Here we provide evidence supporting the key predictions that prestige-biased social learning is used when it constitutes an indirect cue of success, and when success-biased social learning is unavailable. We ran an online experiment (n = 269) in which participants could copy each other in real-time to score points on a general-knowledge quiz. Our implementation of 'prestige' was the number of times someone had previously been copied by others. Importantly, prestige was an emergent property of participants' behaviour during the experiment; no deception or manipulation of prestige was employed at any time. We found that, as predicted, participants used prestige-biased social learning when the prestige cue was an indirect cue of success, and when direct success information was unavailable. This highlights how people flexibly and adaptively employ social learning strategies based on the reliability of the information that such strategies provide.
The first generation of stars (commonly known as population III) are expected to form in low-mass protogalaxies in which molecular hydrogen is the dominant coolant. Radiation from these stars will ...rapidly build up an extragalactic ultraviolet (UV) background capable of photodissociating H2, and it is widely believed that this background will suppress further star formation in low-mass systems. However, star formation will also produce an extragalactic X-ray background. This X-ray background, by increasing the fractional ionization of protogalactic gas, promotes H2 formation and reduces the effectiveness of ultraviolet feedback. In this paper, we examine which of these backgrounds has the dominant effect. Using a simple model for the growth of the UV and X-ray backgrounds, together with a detailed one-dimensional model of protogalactic chemical evolution, we examine the effects of the X-ray backgrounds produced by a number of likely source models. We show that in several cases, the resulting X-ray background is strong enough to offset UV photodissociation in large H2-cooled protogalaxies. On the other hand, small protogalaxies (those with virial temperatures Tvir < 2000 K) remain dominated by the UV background in all of the models we examine. We also briefly investigate the effects of the X-ray background upon the thermal and chemical evolution of the diffuse intergalactic medium.
The first star formation in the Universe is expected to take place within small protogalaxies, in which the gas is cooled by molecular hydrogen. However, if massive stars form within these ...protogalaxies, they may suppress further star formation by photodissociating the H2. We examine the importance of this effect by estimating the time-scale on which significant H2 is destroyed. We show that photodissociation is significant in the least massive protogalaxies, but becomes less so as the protogalactic mass increases. We also examine the effects of photodissociation on dense clumps of gas within the protogalaxy. We find that while collapse will be inhibited in low-density clumps, denser ones may survive to form stars.
Good self-control has been linked to adaptive outcomes such as better health, cohesive personal relationships, success in the workplace and at school, and less susceptibility to crime and addictions. ...In contrast, self-control failure is linked to maladaptive outcomes. Understanding the mechanisms by which self-control predicts behavior may assist in promoting better regulation and outcomes. A popular approach to understanding self-control is the strength or resource depletion model. Self-control is conceptualized as a limited resource that becomes depleted after a period of exertion resulting in self-control failure. The model has typically been tested using a sequential-task experimental paradigm, in which people completing an initial self-control task have reduced self-control capacity and poorer performance on a subsequent task, a state known as ego depletion. Although a meta-analysis of ego-depletion experiments found a medium-sized effect, subsequent meta-analyses have questioned the size and existence of the effect and identified instances of possible bias. The analyses served as a catalyst for the current Registered Replication Report of the ego-depletion effect. Multiple laboratories (k = 23, total N = 2,141) conducted replications of a standardized ego-depletion protocol based on a sequential-task paradigm by Sripada et al. Meta-analysis of the studies revealed that the size of the ego-depletion effect was small with 95% confidence intervals (CIs) that encompassed zero (d = 0.04, 95% CI –0.07, 0.15. We discuss implications of the findings for the ego-depletion effect and the resource depletion model of self-control.
The European Union has named genomics as one of the promising research fields for the development of new health technologies. Major concerns with regard to these fields are, on the one hand, the ...rather slow and limited translation of new knowledge and, on the other hand, missing insights into the impact on public health and health care practice of those technologies that are actually introduced. This paper aims to give an overview of the major assessment instruments in public health health technology assessment (HTA), health needs assessment (HNA) and health impact assessment (HIA) which could contribute to the systematic translation and assessment of genomic health applications by focussing at population level and on public health policy making. It is shown to what extent HTA, HNA and HIA contribute to translational research by using the continuum of translational research (T1–T4) in genomic medicine as an analytic framework. The selected assessment methodologies predominantly cover 2 to 4 phases within the T1–T4 system. HTA delivers the most complete set of methodologies when assessing health applications. HNA can be used to prioritize areas where genomic health applications are needed or to identify infrastructural needs. HIA delivers information on the impact of technologies in a wider scope and promotes informed decision making. HTA, HNA and HIA provide a partly overlapping and partly unique set of methodologies and infrastructure for the translation and assessment of genomic health applications. They are broad in scope and go beyond the continuum of T1–T4 translational research regarding policy translation.
An obituary is presented for Jack Edgar Myers (1913-2006), a well-known scientist in the field of photosynthesis research. The majority of Myers' experiments were conducted with living cultures of ...algae or cyanobacteria, and he interpreted his results within the context of the physiology of the organism.
Yondelis (Trabectedin) is a novel antitumor agent of marine origin extracted from the tunicate Ecteinascidia turbinata. This original compound is active against several human tumors including sarcoma ...and ovarian and breast adenocarcinoma, as evidenced in phase II clinical trials in advanced multitreated patients. Yondelis is a DNA minor groove binder that blocks cell cycle and interferes with inducible gene transcription in a selective manner. In this study, we investigated the immunomodulatory properties of Yondelis on leukocytes. Human blood monocytes were highly susceptible in vitro to its cytotoxic effect and underwent apoptosis at pharmacologically relevant concentrations (5 nmol/L), whereas lymphocytes were up to 5-fold less sensitive. Macrophages differentiated in vitro with macrophage colony-stimulating factor and tumor-associated macrophages (TAM), isolated from patients with ovarian cancer, were also susceptible. At subcytotoxic concentrations, Yondelis inhibited the in vitro differentiation of monocytes to macrophages. In tumor-treated patients, drug infusion caused a selective decrease of monocyte counts and of ex vivo macrophage differentiation. The in vitro production of two proinflammatory mediators, CCL2 and IL-6, was markedly reduced by Yondelis in monocytes, macrophages, TAM, and freshly isolated ovarian tumor cells. The chemokine CCL2 is the major determinant of monocyte recruitment at tumor sites, whereas IL-6 is a growth factor for ovarian tumors. In view of the protumor activity of TAM and of the strong association between chronic inflammation and cancer progression, the inhibitory effect of Yondelis on macrophage viability, differentiation, and cytokine production is likely to contribute to the antitumor activity of this agent in inflammation-associated human tumors.
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