Punishment and Gossip: Sustaining Cooperation in a Public Goods Game

In an environment in which free-riders are better off than cooperators, social control is required to foster and maintain coopera- tion. There are two main paths through which social control can be ap- plied: punishment and reputation. Our experiments explore the efficacy of punishment and reputation on cooperation rates, both in isolation and in combination. Using a Public Goods Game, we are interested in assessing how cooperation rates change when agents can play one of two different reactive strategies, i.e., they can pay a cost in order to reduce the payoff of free-riders, or they can know others\u27 reputation and then either play defect with free-riders, or refuse to interact with them. Co- operation is maintained at a high level through punishment, but also reputation-based partner selection proves effective in maintaining coop- eration. However, when agents are informed about free-riders\u27 reputation and play Defect, cooperation decreases. Finally, a combination of punish- ment and reputation-based partner selection leads to higher cooperation rates

Punish and Voice: Punishment Enhances Cooperation when Combined with Norm-Signalling

Material punishment has been suggested to play a key role in sustaining human cooperation. Experimental findings, however, show that inflicting mere material costs does not always increase cooperation and may even have detrimental effects. Indeed, ethnographic evidence suggests that the most typical punishing strategies in human ecologies (e.g., gossip, derision, blame and criticism) naturally combine normative information with material punishment. Using laboratory experiments with humans, we show that the interaction of norm communication and material punishment leads to higher and more stable cooperation at a lower cost for the group than when used separately. In this work, we argue and provide experimental evidence that successful human cooperation is the outcome of the interaction between instrumental decision-making and the norm psychology humans are provided with. Norm psychology is a cognitive machinery to detect and reason upon norms that is characterized by a salience mechanism devoted to track how much a norm is prominent within a group. We test our hypothesis both in the laboratory and with an agent-based model. The agent-based model incorporates fundamental aspects of norm psychology absent from previous work. The combination of these methods allows us to provide an explanation for the proximate mechanisms behind the observed cooperative behaviour. The consistency between the two sources of data supports our hypothesis that cooperation is a product of norm psychology solicited by norm-signalling and coercive devices

Collective cell durotaxis emerges from long-range intercellular force transmission

The ability of cells to follow gradients of extracellular matrix stiffness—durotaxis—has been implicated in development, fibrosis, and cancer. Here, we found multicellular clusters that exhibited durotaxis even if isolated constituent cells did not. This emergent mode of directed collective cell migration applied to a variety of epithelial cell types, required the action of myosin motors, and originated from supracellular transmission of contractile physical forces. To explain the observed phenomenology, we developed a generalized clutch model in which local stick-slip dynamics of cell-matrix adhesions was integrated to the tissue level through cell-cell junctions. Collective durotaxis is far more efficient than single-cell durotaxis; it thus emerges as a robust mechanism to direct cell migration during development, wound healing, and collective cancer cell invasion.Peer ReviewedPostprint (author's final draft

Counter-punishment, norm-communication and accountability

Presentado como comunicación en HEIDI-CORTEX Behavioral Economics Workshop GATE, celebrado los días 29 y 30 de octubre de 2014 en Ecully (France). Presentado como comunicación el 17 de abril de 2015 en el Second International Meeting on Experimental and Behavioral Social Sciences, celebrado del 15 al 17 de abril de 2015 en Toulouse (Francia)We study whether communication can limit the negative consequences of the use of counterpunishment in a public goods environment. The two dimensions of communication we study are norm communication and accountability, having to justify one’s actions to others. We conduct four experimental treatments, all involving a contribution stage, a punishment stage and a counterpunishment stage. In the first stage there are no communication possibilities. The second treatment allows for communication at the punishment stage and the third asks for a justification message at the counter-punishment stage. The fourth combines the two communication channels of the second and third treatments. We find that the three treatments involving communication at any of the two relevant stages lead to significantly higher contributions than the baseline treatment. The detrimental effect of allowing for counter-punishment is neutralized in the presence of communication possibilities. We find no difference between the three treatments with communication. Separately norm communication and being held accountable work equally well and we find no interaction effect from using them jointly. We also relate our results to those of other treatments without counter-punishment opportunities. The overall pattern of results shows that the key factor is the presence of communication. Whenever it is possible contributions are higher than when it is not, regardless of counter-punishment opportunitiesThe work presented in this paper has been performed in the frame of the MacNorms project (Intramurales de frontera CSIC – PIF08-007) and of the Gloders project (Seventh Framework EU Programme FP7/2007-2013 Grant: 315874). The authors thank the Institute of Cognitive Sciences and Technologies (ISTC-CNR, Rome), the European University Institute, the Spanish Ministerio de Economía y Competitividad (Grant: ECO2011-29847-C02-01) and the Generalitat de Catalunya (Grant: 2009 SGR 820 and Grant 2009SGR1434) for research supportPeer Reviewe

Family management and firm performance in family SMEs: the mediating roles of management control systems and technological innovation

The aim of this research is to analyze the mediating role of the use of management control systems (MCS) and the achievement of technological innovation (TI) in the relationship between family management and firm performance in family small and medium-sized enterprises (SMEs). A questionnaire was conducted by 617 managers of family SMEs in Spain, and our model was tested using partial least squares. Our findings show that both MCS and TI play crucial mediating roles in the understanding of the relationship between family management and firm performance. As a result, family-managed firms that utilize MCS and produce TI are much more likely to generate better performance. These results encourage family managers to use formal MCS because in that way they will contribute to obtaining better firm performance, directly and indirectly through TI. We focus on private family SMEs, because these specific firms contribute significantly to the economies worldwide. This paper contributes to resolve the controversy regarding the relationship between family management and firm performance introducing MCS and TI as mediating factors.Agência financiadora Ministry of Science and Innovation, Spain (MICINN) UID/SOC/04020/2013 Universidad de Malaga Universidad de Cartagenainfo:eu-repo/semantics/publishedVersio

Training/Match External Load Ratios in Professional Soccer Players:A Full-Season Study

The aim of this study was two-fold: (i) to describe the training/match ratios of different external load measures during a full professional soccer season while analyzing the variations between different types of weeks (three, four and five training sessions/week) and (ii) to investigate the relationship between weekly accumulated training loads and the match demands of the same week. Twenty-seven professional soccer players (24.9 ± 3.5 years old) were monitored daily using a 10-Hz global positioning system with a 100-Hz accelerometer. Total distance (TD), running distance (RD), high-speed running (HSR), sprinting distance (SD), player load (PL), number of high accelerations (ACC), and number of high decelerations (DEC) were recorded during training sessions and matches. An individual training/match ratio (TMr) was calculated for each external load measure. Weeks with five training sessions (5dW) presented meaningfully greater TMr than weeks with four (4dW) or three (3dW) training sessions. Additionally, TDratio (TDr) was significantly greater in 5dW than in 3dW (mean differences dif: 1.23 arbitray units A.U.) and 4dW (dif: 0.80 A.U.); HSRr was significantly greater in 5dW than in 3dW (dif: 0.90 A.U.) and 4dW (dif: 0.68 A.U.); and SDr was significantly greater in 5dW than in 3dW (dif: 0.77 A.U.) and 4dW (dif: 0.90 A.U.). Correlations between the weekly training loads and the match demands of the same week were small for PL (r = 0.250 [0.13;0.36]), ACC (r = 0.292 [0.17;0.40]) and DEC (r = 0.236 [0.11;0.35]). This study reveals that ratios of above 1 were observed for specific measures (e.g., HSR, SD). It was also observed that training sessions are not adjusted according to weekly variations in match demands

Machine Learning Framework to Identify Individuals at Risk of Rapid Progression of Coronary Atherosclerosis: From the PARADIGM Registry.

Background Rapid coronary plaque progression (RPP) is associated with incident cardiovascular events. To date, no method exists for the identification of individuals at risk of RPP at a single point in time. This study integrated coronary computed tomography angiography-determined qualitative and quantitative plaque features within a machine learning (ML) framework to determine its performance for predicting RPP. Methods and Results Qualitative and quantitative coronary computed tomography angiography plaque characterization was performed in 1083 patients who underwent serial coronary computed tomography angiography from the PARADIGM (Progression of Atherosclerotic Plaque Determined by Computed Tomographic Angiography Imaging) registry. RPP was defined as an annual progression of percentage atheroma volume ≥1.0%. We employed the following ML models: model 1, clinical variables; model 2, model 1 plus qualitative plaque features; model 3, model 2 plus quantitative plaque features. ML models were compared with the atherosclerotic cardiovascular disease risk score, Duke coronary artery disease score, and a logistic regression statistical model. 224 patients (21%) were identified as RPP. Feature selection in ML identifies that quantitative computed tomography variables were higher-ranking features, followed by qualitative computed tomography variables and clinical/laboratory variables. ML model 3 exhibited the highest discriminatory performance to identify individuals who would experience RPP when compared with atherosclerotic cardiovascular disease risk score, the other ML models, and the statistical model (area under the receiver operating characteristic curve in ML model 3, 0.83 [95% CI 0.78-0.89], versus atherosclerotic cardiovascular disease risk score, 0.60 [0.52-0.67]; Duke coronary artery disease score, 0.74 [0.68-0.79]; ML model 1, 0.62 [0.55-0.69]; ML model 2, 0.73 [0.67-0.80]; all P<0.001; statistical model, 0.81 [0.75-0.87], P=0.128). Conclusions Based on a ML framework, quantitative atherosclerosis characterization has been shown to be the most important feature when compared with clinical, laboratory, and qualitative measures in identifying patients at risk of RPP