When people perform simple actions, they often behave efficiently, minimizing the costs of movement for the expected benefit. The present study addressed the question of whether this efficiency ...scales up to dyads working together to achieve a shared goal: Do people act efficiently as a group (i.e., coefficiently), or do they minimize their own or their partner’s individual costs even if this increases the overall cost for the group? We devised a novel, touch-screen-based, sequential object-transfer task to measure how people choose between different paths to coordinate with a partner. Across multiple experiments, we found that participants did not simply minimize their own or their partner’s movement costs but made coefficient decisions about paths, which ensured that the aggregate costs of movement for the dyad were minimized. These results suggest that people are able and motivated to make coefficient, collectively rational decisions when acting together.
Previous research shows that children evaluate the competence of others based on how effectively someone accomplished a goal, that is, based on the observed outcome of an action (e.g., number of ...attempts needed). Here, we investigate whether 5- to 10-year-old children and adults infer competence from how efficiently someone solves a task by implementing question-asking strategies of varying expected information gains (EIG). Whereas the efficiency of a strategy defined as EIG is a reliable indicator of competence, the observed effectiveness of actions may depend on unrelated external factors, such as luck. Across two experiments conducted in Germany, we varied how efficiently and how effectively different agents solved a 20-questions game (Experiments 1 and 2) and a maze-exploration game (Experiment 2). In Experiment 1 (N = 121), only adults identified a more efficient agent as more competent, and all participants attributed higher competence to agents needing fewer questions even when they employed the same inefficient strategy. In Experiment 2 (N = 220), adults and children from about 8 years onward successfully identified the agents using the more efficient strategy as more competent. Overall, our results suggest that observed effectiveness is a powerful cue for competence even when such an inference may not be warranted and that the ability to make explicit competence judgments based on the efficiency of a strategy alone emerges around 8 years of age, although, as shown in previous work, a more implicit understanding of competence may already be present during the preschool years.
Public Significance Statement
This study investigated the cues young children and adults use to evaluate the competence of someone they observed solving a problem. Children struggle to evaluate competence based on the efficiency of the strategy used until around age 8. Instead, the observed number of steps taken to reach a solution remains a powerful cue for competence throughout childhood and even adulthood. Children's accuracy in making inferences about other people's competence is relevant for their skill growth, socio-cognitive development, and academic achievement. Therefore, exploring and promoting an unbiased understanding of competence, stressing the importance of strategy efficiency, can support children's development in classroom settings and beyond.
Individuals have a drive towards maximising action efficiency, which is reflected in action choices that minimise movement costs to reach a goal. In joint actions, actors prioritise joint efficiency ...or coefficiency, maximising the utility of the joint action even if this comes at a cost to themselves. However, it remains an open question whether actors are willing to unilaterally sacrifice their partner's individual efficiency for the greater good, when forcing a partner to incur additional costs may be interpreted as unfair. In two experiments we explored how participants would choose to distribute a motor task that required either a fair or an unfair distribution of labour. We found that, both whether there was opportunity for reciprocity (Experiment 1) or not (Experiment 2), participants maximised the coefficiency of their joint actions, regardless of how unfair this distribution of labour proved to be regarding the individual action costs. Taken together, our results suggest participants use a rational decision-making framework that prioritises overall efficiency over both individual efficiency and a consideration of fairness.
•Individual agents have a drive towards maximising the efficiency of their actions.•Individuals are also willing to sacrifice their own efficiency to maximise joint utility.•Fairness motivation could interfere with co-efficiency in task distribution.•In two experiments, we find that people reliably prioritise efficiency over fairness.•This supports action planning accounts for joint actions that emphasise rationality.
Gibson's (1979 The Ecological Approach to Visual Perception) ecological approach to visual perception is based on several key notions (i.e., affordance, optic flow, and invariants). Early research ...focused on identifying invariants (π-numbers) to describe affordances using geometric body-scaled measures. Kadar and Koszeghy (2010 International Journal of Sport Psychology 41(3) 80–81) generalized π-numbers to invariant functions (π-functions) to allow dynamically scaled description of driving through gates of variable width. The present study further investigated the dynamic invariants of human locomotion in walking towards and passing through gates. Six participants were instructed to walk through gates of four different sizes with either comfortable or fast walking speed while holding a tray by two hands. Consistent with the results of Kadar and Koszeghy (2010) dynamically-scaled π-functions were identified. The speed control of the approach phase was further assessed in relation to the use of the optical τ parameter derived from optic flow specifying estimated time to contact with the virtual plane defined by the frontal surfaces of the aperture. Aperture size and walking speed have influenced the control of speed at the approach phase: the derivative of τ in the neighborhood of the aperture increased with increasing width of the aperture. Analysis of the approach phase suggests a need for searching an even higher-level invariant structure of the dynamics of this passing through task.
Research on the development of active learning and information search behaviors has been growing rapidly, drawing interest from multiple disciplines, from developmental psychology to cognitive ...science and artificial intelligence. These different perspectives can open pathways to understanding how preschool‐age children grow into adaptive and efficient active learners. However, the lack of a shared vocabulary, operationalizations, and research paradigms has led to limited cross‐talk and some conflicting findings. In this article, we advocate for using a shared operationalization of a “good” information‐search strategy, as a function of its efficiency and effectiveness within a given ecology, based on the information‐theoretic measure of expected information gain and observed behavioral outcomes, respectively. We also discuss factors that should be considered when designing experiments that examine children's information‐search competence, specifically, using formal models as performance benchmarks and accounting for children's prior knowledge, assumptions, and self‐generated goals.
Choosing adequate partners is essential for cooperation, but how children calibrate their partner choice to specific social challenges is unknown. In two experiments, 4‐ to 7‐year‐olds (N = 189, 49% ...girls, mostly White, data collection: 03.2021–09.2022) were presented with partners in possession of different positive qualities. Children then recruited partners for hypothetical tasks that differed with respect to the quality necessary for success. Children and the selected partner either worked together toward a common goal or competed against each other. From age 5, children selectively chose individuals in possession of task‐relevant qualities as cooperative partners while avoiding them as competitors. Younger children chose partners indiscriminately. Children thus learn to strategically adjust their partner choice depending on context‐specific task demands and different social goals.
Successful performance in cooperative activities relies on efficient task distribution between co-actors. Previous research found that people often forgo individual efficiency in favor of ...co-efficiency (i.e., joint-cost minimization) when planning a joint action. The present study investigated the cost computations underlying co-efficient decisions. We report a series of experiments that tested the hypothesis that people compute the joint costs of a cooperative action sequence by summing the individual action costs of their co-actor and themselves. We independently manipulated the parameters quantifying individual and joint action costs and tested their effects on decision making by fitting and comparing Bayesian logistic regression models. Our hypothesis was confirmed: people weighed their own and their partner’s costs similarly to estimate the joint action costs as the sum of the two individual parameters. Participants minimized the aggregate cost to ensure co-efficiency. The results provide empirical support for behavioral economics and computational approaches that formalize cooperation as joint utility maximization based on a weighted sum of individual action costs.
Modelling and analysis of spatiotemporal characteristics of plant invasion can help in mapping and predicting the spread of invasive plants. The aim of our research was to investigate the ...spatiotemporal variability of five common invasive plant species (Ailanthus altissima, Asclepias syriaca, Elaeagnus angustifolia, Robinia pseudoacacia, and Solidago spp.) within different land cover (ecosystem)-type categories. The basis of the study was the National Geospatial Database of Invasive Plants (NGDIP) of Hungary, and the ecosystem types of the Ecosystem Map of Hungary (EMH). The GIS-based analysis of the detailed occurrence database of the invasive species (NGDIP) and the thematic land-cover (ecosystem)-type maps (EMH) examined allow us to answer the question of in which habitat types the occurrence and distribution of the given invasive plant has stagnated, decreased, or increased between 2006 and 2018. We developed a methodology with relevant data sources and demonstrated invasion variation, which can be used for future management planning and invasive biology research. Our results show that Asclepias syriaca and Robinia pseudoacacia are increasingly threatening grasslands and are also spreading more intensively in complex cultivated areas. The occurrences of Ailanthus altissima and Asclepias syriaca are declining in built-up areas due to the increasingly extreme environmental conditions of cities or modified urban planning. The spread of Solidago spp. is increasingly common in wetlands, threatening the biodiversity of floodplain (riparian) vegetation.
High sodium intake and inadequate potassium intake are associated with high blood pressure. The elderly are more salt sensitive than other age groups, yet a reliable estimate of the dietary sodium ...and potassium intake of this age group in Hungary is unavailable. The study aimed to estimate the sodium and potassium intakes in the Hungarian elderly from 24 h urine sodium and potassium excretion. In this cross-sectional study, participants were selected from patients of general practitioners practicing in western Hungary. The participants comprised 99 men and 90 women (mean age 67.1 (SD 5.4 years) who participated in the Biomarker2019 survey and returned a complete 24 h urine collection. We assessed dietary sodium and potassium by determining 24 h urinary sodium and potassium excretions and 3-day dietary records. The mean urinary sodium was 188.8 (73.5) mmoL/day, which is equivalent to 11.0 g of salt/day; and the mean urinary potassium was 65.8 (24.3) mmoL/day, which is equivalent to 3.03 g of potassium/day, after adjusting for non-urinary potassium losses. Only 7% of the subjects met the World Health Organization’s recommended target of less than 5 g of salt/day, and 33% consumed at least the recommended potassium amount of 3.5 g/day, based on the estimates from 24 h urine excretion. For most elderly, sodium intake exceeds, and potassium does not reach, dietary recommendations. The results underline the need to intensify salt reduction efforts in Hungary.
The SARS-CoV-2 variant B.1.1.7 was first identified in December, 2020, in England. We aimed to investigate whether increases in the proportion of infections with this variant are associated with ...differences in symptoms or disease course, reinfection rates, or transmissibility.
We did an ecological study to examine the association between the regional proportion of infections with the SARS-CoV-2 B.1.1.7 variant and reported symptoms, disease course, rates of reinfection, and transmissibility. Data on types and duration of symptoms were obtained from longitudinal reports from users of the COVID Symptom Study app who reported a positive test for COVID-19 between Sept 28 and Dec 27, 2020 (during which the prevalence of B.1.1.7 increased most notably in parts of the UK). From this dataset, we also estimated the frequency of possible reinfection, defined as the presence of two reported positive tests separated by more than 90 days with a period of reporting no symptoms for more than 7 days before the second positive test. The proportion of SARS-CoV-2 infections with the B.1.1.7 variant across the UK was estimated with use of genomic data from the COVID-19 Genomics UK Consortium and data from Public Health England on spike-gene target failure (a non-specific indicator of the B.1.1.7 variant) in community cases in England. We used linear regression to examine the association between reported symptoms and proportion of B.1.1.7. We assessed the Spearman correlation between the proportion of B.1.1.7 cases and number of reinfections over time, and between the number of positive tests and reinfections. We estimated incidence for B.1.1.7 and previous variants, and compared the effective reproduction number, Rt, for the two incidence estimates.
From Sept 28 to Dec 27, 2020, positive COVID-19 tests were reported by 36 920 COVID Symptom Study app users whose region was known and who reported as healthy on app sign-up. We found no changes in reported symptoms or disease duration associated with B.1.1.7. For the same period, possible reinfections were identified in 249 (0·7% 95% CI 0·6–0·8) of 36 509 app users who reported a positive swab test before Oct 1, 2020, but there was no evidence that the frequency of reinfections was higher for the B.1.1.7 variant than for pre-existing variants. Reinfection occurrences were more positively correlated with the overall regional rise in cases (Spearman correlation 0·56–0·69 for South East, London, and East of England) than with the regional increase in the proportion of infections with the B.1.1.7 variant (Spearman correlation 0·38–0·56 in the same regions), suggesting B.1.1.7 does not substantially alter the risk of reinfection. We found a multiplicative increase in the Rt of B.1.1.7 by a factor of 1·35 (95% CI 1·02–1·69) relative to pre-existing variants. However, Rt fell below 1 during regional and national lockdowns, even in regions with high proportions of infections with the B.1.1.7 variant.
The lack of change in symptoms identified in this study indicates that existing testing and surveillance infrastructure do not need to change specifically for the B.1.1.7 variant. In addition, given that there was no apparent increase in the reinfection rate, vaccines are likely to remain effective against the B.1.1.7 variant.
Zoe Global, Department of Health (UK), Wellcome Trust, Engineering and Physical Sciences Research Council (UK), National Institute for Health Research (UK), Medical Research Council (UK), Alzheimer's Society.
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