Shared responsibility in collective decisions

Give us a hand, mate! A holistic review of research on human-machine teaming

Defence has a significant interest in the use of artificial intelligence (AI)-based technologies to address some of the challenges it faces. At the core of future military advantage will be the effective integration of humans and AI into human-machine teams (HMT) that leverages the capabilities of people and technologies to outperform adversaries. Realising the full potential of these technologies will depend on understanding the relative strengths of humans and machines, and how we design effective integration to optimise performance and resilience across all use cases and environments.Since the first robot appeared on the assembly line, machines have effectively augmented human capability and performance; however, they fall short of being a team member-someone you can ask to give you a hand! Working in teams involves collaboration, adaptive and dynamic interactions between team members to achieve a common goal. Currently, human-machine partnership is typically one of humans and machines working alongside each other, with each conducting discrete functions within predicable process and environments. However, with recent advances in neuroscience and AI, we can now envisage the possibility of HMT, not just in physical applications, but also complex cognitive tasks.This paper provides a holistic review of the research conducted in the field of HMT from experts working in this area. It summarises completed and ongoing studies and research in the UK and USA by a broad group of researchers. This work was presented in the HMT thematic session at the Sixth International Congress on Soldiers' Physical Performance (ICSPP23 London).

Experience and advice consequences shape information sharing strategies

Individuals often rely on the advice of more experienced peers to minimise uncertainty and increase success likelihood. In most domains where knowledge is acquired through experience, advisers are themselves continuously learning. Here we examine the way advising behaviour changes throughout the learning process, and the way individual traits and costs and benefits of giving advice shape this behaviour. We ran a series of experiments implementing a decision task within a reinforcement learning framework, where participants could decide to share their choices as advice to others. Participants were overall likely to share their choices as advice, even on the first trial before learning. Tendency to share advice and advice quality increased as advisers learned about the value of choices, and moved from exploratory to exploitative behaviour. The introduction of consequences to advising resulted in a shift of the overall tendency to give advice, lowering it when advising implicated monetary loss, and increasing it when advising held reputational value. Individual differences in social anxiety levels were associated with lower tendency to share exploratory decisions. Our results show that advisers tend to share choices that are backed by their own experience, but that this relationship can be altered by advice-consequences and individual traits.

The effect of an embodied intervention on responsibility: put a load on one's shoulder

Responsibility is an essential part of our social life. Although responsibility is an abstract concept, it can be represented with concrete ideas through conceptual metaphor. Expressions like "carry a lot of responsibility," "shoulder the responsibility" shows that responsibility can be understood as a load on shoulder that one has to carry. Accordingly, this study tests the question that does putting a burden on one's shoulder makes him/her more responsible or not. In order to investigate this, on each trial, we asked participants to decide between risky situations that vary in magnitude, probability of win/lose, and the ambiguity level in two conditions: "self" and 'group." Each subject wears a vest with a load on each shoulder in half of the trials. As expected, Most of participants choose to defer on the group trials more than on the self-trials. This difference between numbers of deferring in group and self conditions is called responsibility aversion. Results indicate that responsibility aversion scores are lower (responsibility-taking was greater) in the state of wearing the vest than in the form of not wearing the vest significantly. We provided evidence that the abstract concept of responsibility is linked to bodily experiences of feeling load on the shoulder consistent with an embodied cognition theory.

Action-based confidence sharing and collective decision making

Joint action research explores how multiple humans can coordinate their movements to achieve common goals. When there is uncertainty about the joint goal, individuals need to integrate their perceptual information of the environment to collaboratively determine their new goal. To ensure that a group reaches a consensus about the goal, collective decision making among the individuals is required. Collective decision making can be facilitated by nonverbal expressions of opinions and associated confidence levels. Here, we show that confidence sharing in groups of 2, 3, and 4 individuals can be studied using their trajectories when jointly moving toward one of several options. We found that both opinions and confidence levels can be distinguished in individual movement trajectories, and found that movement features can predict an individual's influence. Our results suggest that movement trajectories are a valid way to study confidence sharing in human collective decision making.

How large language models can reshape collective intelligence

Collective intelligence underpins the success of groups, organizations, markets and societies. Through distributed cognition and coordination, collectives can achieve outcomes that exceed the capabilities of individuals-even experts-resulting in improved accuracy and novel capabilities. Often, collective intelligence is supported by information technology, such as online prediction markets that elicit the 'wisdom of crowds', online forums that structure collective deliberation or digital platforms that crowdsource knowledge from the public. Large language models, however, are transforming how information is aggregated, accessed and transmitted online. Here we focus on the unique opportunities and challenges this transformation poses for collective intelligence. We bring together interdisciplinary perspectives from industry and academia to identify potential benefits, risks, policy-relevant considerations and open research questions, culminating in a call for a closer examination of how large language models affect humans' ability to collectively tackle complex problems.

Co-perceiving: Bringing the social into perception

Humans and other animals possess the remarkable ability to effectively navigate a shared perceptual environment by discerning which objects and spaces are perceived by others and which remain private to themselves. Traditionally, this capacity has been encapsulated under the umbrella of joint attention or joint action. In this comprehensive review, we advocate for a broader and more mechanistic understanding of this phenomenon, termed co-perception. Co-perception encompasses the sensitivity to the perceptual engagement of others and the capability to differentiate between objects perceived privately and those perceived commonly with others. It represents a distinct concept from mere simultaneous individual perception. Moreover, discerning between private and common objects doesn't necessitate intricate mind-reading abilities or mutual coordination. The act of perceiving objects as either private or common provides a comprehensive account for social scenarios where individuals simply share the same context or may even engage in competition. This conceptual framework encourages a re-examination of classical paradigms that demonstrate social influences on perception. Furthermore, it suggests that the impacts of shared experiences extend beyond affective responses, also influencing perceptual processes. This article is categorized under: Psychology > Attention Philosophy > Foundations of Cognitive Science Philosophy > Psychological Capacities.

A Delphi Panel of People With Parkinson's Disease Regarding Responsibility: Toward a Preliminary Taxonomy

IMPORTANCE

A sense of agency is associated with complex occupation-related responsibilities. A taxonomy can guide clinicians in enhancing responsibility in patients with Parkinson's disease (PwPD).

OBJECTIVE

To (1) discover levels of responsibility in occupations for PwPD and (2) propose a taxonomy for occupations.

DESIGN

A two-round Delphi study with PwPD and a one-round Delphi study with international experts.

SETTING

Electronic survey.

PARTICIPANTS

PwPD (N = 75) and international experts (N = 8).

OUTCOMES AND MEASURES

PwPD expressed their levels of an inherent sense of responsibility for each occupation (1 = very low responsibility, 5 = very high responsibility). International experts rated their level of agreement (5 = strongly agree, 1 = strongly disagree) with each dimension of the taxonomy. A consensus was determined to have been reached if the interquartile range was ≤1 and 70% agreement in two adjacent categories was achieved.

RESULTS

Thirty-three occupation categories were deemed as having very high to moderate responsibility for PwPD. Consequences of actions and the presence of others made up the two-dimensional responsibility taxonomy. Occupations have more challenging responsibility characteristics when they are performed with free choice, a level of high physical effort, alone, and with moral consequences.

CONCLUSIONS AND RELEVANCE

This study yielded the first consensus among PwPD regarding responsibility in occupations as well as a classification system for charting the complexity of responsibility in occupations. The occupation list we have created can be beneficial to health care professionals when providing interventions or conducting outcome assessments. Plain-Language Summary: When planning interventions for patients with Parkinson's disease, it can be helpful for clinicians to be aware of patients' perspectives regarding their sense of responsibility to perform occupations. The use of a systematic sequence of challenging occupations with responsibility attributes ranging from less complex to more complex can help enhance patient occupational participation.

The contribution of sensory information asymmetry and bias of attribution to egocentric tendencies in effort comparison tasks

When comparing themselves with others, people often evaluate their own behaviors more favorably. This egocentric tendency is often categorized as a bias of attribution, with favorable self-evaluation resulting from differing explanations of one's own behavior and that of others. However, studies on information availability in social contexts offer an alternative explanation, ascribing egocentric biases to the inherent informational asymmetries between performing an action and merely observing it. Since biases of attribution and availability often co-exist and interact with each other, it is not known whether they are both necessary for the egocentric biases to emerge. In this study, we used a design that allowed us to directly compare the contribution of these two distinct sources of bias to judgements about the difficulty of an effortful task. Participants exhibited no attribution bias as judgements made for themselves did not differ from those made for others. Importantly, however, participants perceived the tasks they actively performed to be harder than the tasks they observed, and this bias was magnified as the overall task difficulty increased. These findings suggest that information asymmetries inherent to the difference between actively performing a task and observing it can drive egocentric biases in effort evaluations on their own and without a contribution from biases of attribution.

Emergence and collapse of reciprocity in semiautomatic driving coordination experiments with humans

Forms of both simple and complex machine intelligence are increasingly acting within human groups in order to affect collective outcomes. Considering the nature of collective action problems, however, such involvement could paradoxically and unintentionally suppress existing beneficial social norms in humans, such as those involving cooperation. Here, we test theoretical predictions about such an effect using a unique cyber-physical lab experiment where online participants (N = 300 in 150 dyads) drive robotic vehicles remotely in a coordination game. We show that autobraking assistance increases human altruism, such as giving way to others, and that communication helps people to make mutual concessions. On the other hand, autosteering assistance completely inhibits the emergence of reciprocity between people in favor of self-interest maximization. The negative social repercussions persist even after the assistance system is deactivated. Furthermore, adding communication capabilities does not relieve this inhibition of reciprocity because people rarely communicate in the presence of autosteering assistance. Our findings suggest that active safety assistance (a form of simple AI support) can alter the dynamics of social coordination between people, including by affecting the trade-off between individual safety and social reciprocity. The difference between autobraking and autosteering assistance appears to relate to whether the assistive technology supports or replaces human agency in social coordination dilemmas. Humans have developed norms of reciprocity to address collective challenges, but such tacit understandings could break down in situations where machine intelligence is involved in human decision-making without having any normative commitments.

Towards planetary oral health

It is time to consider the protection of our environment as a major public health issue in oral medicine. Evidence shows that activities related to dental practice, such as patient transportation, use of rare materials and chemicals, or energy consumption, affect our ecosystems and contribute to the global degradation we are increasingly observing. The degradation of our environment is considered the greatest threat to our health. Exposure of oral tissues to multiple environmental factors can lead to pathological conditions. In addition to these direct effects, there are more complex phenomena, leading to co-deficits in the health of populations. The example of the sugar industry illustrates the systemic failures resulting in the double degradation of the environment and the health of individuals. Face with these dynamically interacting phenomena, human communities must consider systemic responses such as those described in this article. The dental community will need to do its part and consider global oral health as a central issue. This conceptual work will help define the innovations and action needed to ensure equitable practice that respects planetary limits.

A comparison of the effects of occupation-based interventions with and without responsibility feedback and conventional interventions on participation in people with idiopathic Parkinson's disease: study protocol for a randomized controlled trial

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder with debilitating motor and non-motor symptoms which affect participation in meaningful occupations. Occupation-based interventions can improve participation in people with PD. Evidence for incorporating structured and intensive occupational therapy by considering the concept of responsibility is lacking for this population. This trial will compare the effects of occupation-based interventions with and without responsibility feedback and conventional interventions on participation in people with idiopathic PD.

METHODS

A total of 45 people with PD, between 35 and 85 years old and Hoehn and Yahr stages between I to III, will be recruited from movement disorder centers for this three-armed study. Participants will be randomized into three groups (occupation-based interventions with responsibility feedback, occupation-based interventions without responsibility feedback, and conventional interventions). All participants will receive intervention for 24 sessions during a period of 12 weeks (2 sessions per week). The primary outcome measure will be participation satisfaction. Participation frequency and restriction, self-perceived performance, performance satisfaction, motivation, volition, sense of agency, responsibility, physical activity, community integration, activities of daily living (ADL), instrumental ADL, upper extremity function, balance, fatigue, and quality of life will be measured as secondary outcome measures. All outcomes will be measured at baseline, session 9, session 17, post-intervention (week 13), and follow-up (week 25).

DISCUSSION

This home-based high-intensity, structured, client-centered, and occupation-based intervention will be conducted by utilizing the concept of responsibility. This proposed trial may result in enhanced participation that would benefit other motor and non-motor symptoms in people living with PD. Findings from this proposed study are expected to expand the knowledge of clinicians and help them in evidence-based decision-making processes.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20140304016830N13. Registered on August 19, 2022.

Social interoception: Perceiving events during cardiac afferent activity makes people more suggestible to other people's influence

Our judgements are often influenced by other people's views and opinions. Interoception also influences decision making, but little is known about its role in social influence and particularly, the extent to which other people may influence our decisions. Across two experiments, using different forms of social influence, participants judged the trustworthiness of faces presented either during the systolic phase of the cardiac cycle, when baroreceptors convey information from the heart to the brain, or during diastolic phase, when baroreceptors are quiescent. We quantified the extent to which participants changed their minds (as an index of social influence) following the social feedback, in order to compare two competing hypotheses. According to the Arousal-Confidence Hypothesis, cardiac signals create a context of heightened bodily arousal that increases confidence in perceptual judgements. People should, therefore, be less subject to social influence during systole. By contrast, according to the Uncertainty-Conformity Hypothesis, cardiac signals increase neural noise and sensory attenuation, such that people should display greater effects of social influence during systole, as they then underweight private interoceptive signals in favour of the external social information. Across two studies that used different kind of social interactions, we found that participants changed their minds more when faces were presented at systole. Our results, therefore, support the Uncertainly-Conformity hypothesis and highlight how cardiac afferent signals contribute to shape our social decision-making in different types of social interactions.

Making a positive difference: Criticality in groups

How critical are individual members perceived to be for their group's performance? In this paper, we show that judgments of criticality are intimately linked to considering responsibility. Prospective responsibility attributions in groups are relevant across many domains and situations, and have the potential to influence motivation, performance, and allocation of resources. We develop various models that differ in how the relationship between criticality and responsibility is conceptualized. To test our models, we experimentally vary the task structure (disjunctive, conjunctive, and mixed) and the abilities of the group members (which affects their probability of success). We show that both factors influence criticality judgments, and that a model which construes criticality as anticipated credit best explains participants' judgments. Unlike prior work that has defined criticality as anticipated responsibility for both success and failures, our results suggest that people only consider the possible outcomes in which an individual contributed to a group success, but disregard group failure.

Intelligence brings responsibility - Even smart AI assistants are held responsible

People will not hold cars responsible for traffic accidents, yet they do when artificial intelligence (AI) is involved. AI systems are held responsible when they act or merely advise a human agent. Does this mean that as soon as AI is involved responsibility follows? To find out, we examined whether purely instrumental AI systems stay clear of responsibility. We compared AI-powered with non-AI-powered car warning systems and measured their responsibility rating alongside their human users. Our findings show that responsibility is shared when the warning system is powered by AI but not by a purely mechanical system, even though people consider both systems as mere tools. Surprisingly, whether the warning prevents the accident introduces an outcome bias: the AI takes higher credit than blame depending on what the human manages or fails to do.

Consensus on Feedback Statements That Create Responsibility Among People With Parkinson's Disease: A Delphi Study

IMPORTANCE

Sense of agency is associated with a sense of responsibility, which is essential to performing goal-directed occupations.

OBJECTIVE

To reach consensus on a set of extrinsic feedback statements that have the potential to create a sense of responsibility among patients with neurological disorders in the course of performing daily or social occupations.

DESIGN

Anonymous Delphi study with two rounds with international experts and one round with Irani patients with Parkinson's disease (PD).

SETTING

Electronic survey.

PARTICIPANTS

One hundred experts and 73 patients with idiopathic PD.

OUTCOMES AND MEASURES

Experts and patients anonymously rated (5 = strongly agree/very effective, 4 = agree/effective, 3 = neither agree nor disagree/uncertain, 2 = disagree/ineffective, 1 = strongly disagree/very ineffective) their level of agreement with each survey statement and the effectiveness of each statement in creating a sense of responsibility in the course of performing daily or social occupations. Consensus was set as an interquartile range of ≤1 and ≥70% agreement in two adjacent categories of a Likert scale.

RESULTS

In the experts' first round, consensus was reached on the level of agreement and effectiveness of 18 statements. In the second round, final consensus was achieved on all statements. In the one patient round, patients reached consensus on all statements. Finally, 34 statements were rated as 4 or 5 in terms of agreement and effectiveness, based on the opinions of experts and patients.

CONCLUSIONS AND RELEVANCE

This study has produced a collection of feedback statements that might be useful in occupation-based interventions. What This Article Adds: Extrinsic responsibility feedback delivered while administering occupation-based interventions may increase volition, motivation, and engagement.

Occupations to Enhance Responsibility Among Patients With Parkinson's Disease: An International Delphi Study

IMPORTANCE

The ability to perform voluntary actions is disrupted in Parkinson's disease (PD). Voluntary activities play a critical role in generating sense of agency, which underpins the concept of responsibility for people's daily occupations and their outcomes. According to this concept, the dearth of research regarding the concept of responsibility in rehabilitation hampers practitioners in delivering evidence-based care.

OBJECTIVE

To generate a list of occupations that enhance an inherent sense of responsibility among people with PD that is based on consensus among experts.

DESIGN

An anonymous and iterative Delphi study with two rounds.

SETTING

Electronic survey.

PARTICIPANTS

One hundred sixteen experts participated in the first round of the study, and 95 participated in the second round.

OUTCOMES AND MEASURES

Panelists rated the level of inherent responsibility in each occupation and the importance of types of patient-related information on a 5-point Likert scale. Consensus was defined as reaching an interquartile range of >1.

RESULTS

In the first round, consensus was reached on 19 occupations and all 38 types of patient-related information. Also, an additional 15 occupations and 16 types of patient-related information were added to the lists. Consensus was reached for all occupations and patient-related information presented in the second round.

CONCLUSIONS AND RELEVANCE

Our results indicate that 61 occupations were deemed to enhance a moderate to a very high inherent sense of responsibility among people with PD. In addition, a wide range of patient-related information is considered very important or important while these occupation-focused interventions are delivered. What This Article Adds: Subjective knowledge of one's actions and their consequences lies behind people's daily occupations. Considering this knowledge when administering occupation-focused interventions can be beneficial for individuals with PD.

Shared responsibility for decision-making in NICU: A scoping review

BACKGROUND

Shared responsibility is an essential part of family-centred care and it characterizes the relationship between parents and healthcare professionals. Despite this, little is known about their shared responsibility for decision-making in neonatal intensive care units.

AIM

The aim of this scoping review was to identify previous studies on the subject and to summarize the knowledge that has been published so far.

METHOD

The review was conducted using electronic searches in the CINAHL, PubMed, Scopus and PsycINFO databases and manual searches of the reference lists of the selected papers. The searches were limited to peer-reviewed papers that had been published in English from 2010 to September 2021. The data were selected based on inclusion and exclusion criteria and the findings were inductively summarized. We identified eight papers that met the inclusion criteria.

ETHICAL CONSIDERATIONS

The scoping review was conducted according to good scientific practice by respecting authorship and reporting the study processes accurately, honestly and transparently.

RESULTS

The results showed that shared responsibility for decision-making was based on the parents' intentions, but the degree to which they were willing to take responsibility varied. The facilitating and inhibiting factors for shared responsibility for decision-making were related to the communication between parents and professionals. The impact was related to the parents' emotions.

CONCLUSION

It is essential that parents and professionals negotiate how both parties will contribute to their shared responsibility for decision-making. This will enable them to reach a mutual understanding of what is in the infants' best interests and to mitigate the emotional burden of decisions in neonatal intensive care units. More research is needed to clarify the concept of shared responsibility for decision-making in this intensive care context.

Compromising improves forecasting

Predicting the future can bring enormous advantages. Across the ages, reliance on supernatural foreseeing was substituted by the opinion of expert forecasters, and now by collective intelligence approaches which draw on many non-expert forecasters. Yet all of these approaches continue to see individual forecasts as the key unit on which accuracy is determined. Here, we hypothesize that compromise forecasts, defined as the average prediction in a group, represent a better way to harness collective predictive intelligence. We test this by analysing 5 years of data from the Good Judgement Project and comparing the accuracy of individual versus compromise forecasts. Furthermore, given that an accurate forecast is only useful if timely, we analyze how the accuracy changes through time as the events approach. We found that compromise forecasts are more accurate, and that this advantage persists through time, though accuracy varies. Contrary to what was expected (i.e. a monotonous increase in forecasting accuracy as time passes), forecasting error for individuals and for team compromise starts its decline around two months prior to the event. Overall, we offer a method of aggregating forecasts to improve accuracy, which can be straightforwardly applied in noisy real-world settings.

Can individual subjective confidence in training questions predict group performance in test questions?

When people have to solve many tasks, they can aggregate diverse individuals' judgments using the majority rule, which often improves the accuracy of judgments (wisdom of crowds). When aggregating judgments, individuals' subjective confidence is a useful cue for deciding which judgments to accept. However, can confidence in one task set predict performance not only in the same task set, but also in another? We examined this issue through computer simulations using behavioral data obtained from binary-choice experimental tasks. In our simulations, we developed a "training-test" approach: We split the questions used in the behavioral experiments into "training questions" (as questions to identify individuals' confidence levels) and "test questions" (as questions to be solved), similar to the cross-validation method in machine learning. We found that (i) through analyses of behavioral data, confidence in a certain question could predict accuracy in the same question, but not always well in another question. (ii) Through a computer simulation for the accordance of two individuals' judgments, individuals with high confidence in one training question tended to make less diverse judgments in other test questions. (iii) Through a computer simulation of group judgments, the groups constructed from individuals with high confidence in the training question(s) generally performed well; however, their performance sometimes largely decreased in the test questions especially when only one training question was available. These results suggest that when situations are highly uncertain, an effective strategy is to aggregate various individuals regardless of confidence levels in the training questions to avoid decreasing the group accuracy in test questions. We believe that our simulations, which follow a "training-test" approach, provide practical implications in terms of retaining groups' ability to solve many tasks.

Flexible use of confidence to guide advice requests

Subjective confidence plays an important role in guiding behavior, for example, people typically commit to decisions immediately if high in confidence and seek additional information if not. The present study examines whether people are flexible in their use of confidence, such that the mapping between confidence and behavior is not fixed but can instead vary depending on the specific context. To investigate this proposal, we tested the hypothesis that the seemingly natural relationship between low confidence and requesting advice varies according to whether people know, or do not know, the quality of the advice. Participants made an initial perceptual judgement and then chose between re-sampling evidence or receiving advice from a virtual advisor, before committing to a final decision. The results indicated that, when objective information about advisor reliability was not available, participants selected advice more often when their confidence was high rather than when it was low. This pattern reflects the use of confidence as a feedback proxy to learn about advisor quality: Participants were able to learn about the reliability of advice even in the absence of feedback and subsequently requested more advice from better advisors. In contrast, when participants had prior knowledge about the reliability of advisors, they requested advice more often when their confidence was low, reflecting the use of confidence as a self-monitoring tool signaling that help should be solicited. These findings indicate that people use confidence in a way that is context-dependent and directed towards achieving their current goals.

The Effectiveness of the Multiple-Attending-Physicians System Compared With the Single Attending-Physician System in Inpatient Setting: A Mixed-Method Study

OBJECTIVES

Medical facilities have been required to effectively utilize insufficient human resources in many countries. Therefore, we qualitatively and quantitively compared physicians' working burden, and assessed advantages and disadvantages of the single- and the multiple-attending physicians systems in inpatient care.

METHODS

In this cross-sectional study, we extracted electronic health record of patients from a hospital in Japan from April 2017 to October 2018 to compare anonymous statistical data between the single-attending and multiple-attending-physicians system. Then, we conducted a questionnaire survey for all physicians of single and multiple-attending systems, asking about their physical and psychiatric workload, and their reasons and comments on their working styles.

RESULTS

The average length of hospital stay was significantly shorter in the multiple-attending system than in the single-attending system, while patients' age, gender, and diagnoses were similar. From the questionnaire survey, no significant difference was found in all categories although physical burden in multiple-attending system tended to be lower than that in single-attending system. Advantages of multiple-attending system extracted from qualitative analysis are (1) improvement of physicians' quality of life (QOL), (2) lifelong-learning effect, and (3) improving the quality of medical care, while disadvantages were (1) risk of miscommunications, (2) conflicting treatment policies among physicians, and (3) patients' concern.

CONCLUSIONS

The multiple-attending physician system in the inpatient setting can reduce the average length of stay for patients and also reduce the physical burden on physicians without compromising their clinical performance.

Experimental evidence of the impact of framing of actors and victims in conservation narratives

Media narratives play a crucial role in framing marine conservation dilemmas by depicting human actors, such as fish consumers or the fishing industry, as responsible for negative effects of their actions on species and ecosystems. However, there is little evidence documenting how such narratives affect preferences for reducing bycatch. Behavioral science research shows that people can act less prosocially when more actors are responsible for a collective outcome (responsibility diffusion effect) and when more victims need to be helped (compassion fade effect); thus, the media's framing of actors and victims may have a significant effect on preferences. We conducted the first test of responsibility diffusion and compassion fade in a marine context in an online experiment (1548 participants in the United Kingdom). In 9 media narratives, we varied the type of actors responsible for fisheries bycatch (e.g., consumers and industry) and victims (e.g., a single species, multiple species, and ecosystems) in media narratives and determined the effects of the narratives on participants' support for bycatch policies and intentions to alter fish consumption. When responsibility for negative effects was attributed to consumers and industry, the probability of participants reporting support for fisheries policies (e.g., bycatch enforcement or consumer taxes) was ∼30% higher (odds ratio = 1.32) than when only consumers were attributed responsibility. These effects were primarily driven by female participants. Narratives had no effect on personal intentions to consume fish. Varying the type of victim had no effect on policy support and intentions. Our results suggest that neither responsibility diffusion nor compassion fade automatically follows from increasing the types of actors and victims in media narratives and that effects can depend on the type of outcome and population subgroup.

Shared Responsibility Decreases the Sense of Agency in the Human Brain

Sharing responsibility in social decision-making helps individuals use the flexibility of the collective context to benefit themselves by claiming credit for good outcomes or avoiding the blame for bad outcomes. Using magnetoencephalography, we examined the neuronal basis of the impact that social context has on this flexible sense of responsibility. Participants performed a gambling task in various social contexts and reported feeling less responsibility when playing as a member of a team. A reduced magnetoencephalography outcome processing effect was observed as a function of decreasing responsibility at 200 msec post outcome onset and was centered over parietal, central, and frontal brain regions. Before outcome revelation in socially made decisions, an attenuated motor preparation signature at 500 msec after stimulus onset was found. A boost in reported responsibility for positive outcomes in social contexts was associated with increased activity in regions related to social and reward processing. Together, these results show that sharing responsibility with others reduces agency, influencing pre-outcome motor preparation and post-outcome processing, and provides opportunities to flexibly claim credit for positive outcomes.

Diffusion of punishment in collective norm violations

People assign less punishment to individuals who inflict harm collectively, compared to those who do so alone. We show that this arises from judgments of diminished individual causal responsibility in the collective cases. In Experiment 1, participants (N = 1002) assigned less punishment to individuals involved in collective actions leading to intentional and accidental deaths, but not failed attempts, emphasizing that harmful outcomes, but not malicious intentions, were necessary and sufficient for the diffusion of punishment. Experiments 2.a compared the diffusion of punishment for harmful actions with 'victimless' purity violations (e.g., eating a dead human's flesh as a group; N = 752). In victimless cases, where the question of causal responsibility for harm does not arise, diffusion of collective responsibility was greatly reduced-an outcome replicated in Experiment 2.b (N = 479). Together, the results are consistent with discounting in causal attribution as the underlying mechanism of reduction in proposed punishment for collective harmful actions.

Bystanders Join in Cyberbullying on Social Networking Sites: The Deindividuation and Moral Disengagement Perspectives

Bystanders Join in Cyberbullying on Social Networking Sites: The Deindividuation and Moral Disengagement Perspectives

Cyberbullying on social networking sites escalates when bystanders join in the bullying. Bystanders’ joining-in behaviors reinforce the abuse, expose victims to a larger audience, and encourage further abuse by signaling their approval of the aggressive behavior. This study developed an integrative model that explains bystanders’ joining-in cyberbullying behaviors on SNSs to offer actionable insights into reducing such harmful behaviors. We tested the model using 1,179 responses using a scenario survey study. Our findings suggest that IT artifacts (including digital profile, search and privacy, relational ties, and network transparency) activated two key mechanisms that lead to cyberbullying joining-in behaviors: (i) the deindividuation experiences that attenuate self-identity and put salience on group/social identity, and (ii) the moral disengagement practices that permit the exercise of cognitive maneuvers to justify group-interested choices that do not align with social standard. The findings explain why people who do not know each other gang up to bully a target on social media. Platform owners who wish to discourage bystanders from joining in undesirable activities may consider regulating how users could share and access digital resources in a social network and should acknowledge the influence of social identity in igniting, driving, and prolonging harmful online group behaviors.

What makes us act together? On the cognitive models supporting humans’ decisions for joint action

We face tasks every day that we can solve alone but decide to solve together with others. When do we choose to act together vs. alone? How long do we persist in working together when doing so is difficult? Do we prefer to act together when times are uncertain? An open question in joint action research is under what conditions humans prefer to act together or alone to achieve a certain goal, and whether their preference is based on a utility calculus that takes into account the costs and benefits associated with individual and joint action alternatives. Research on cooperation reveals that frequent engagement in joint activities provides high survival benefits, as it allows individuals to achieve goals together that are otherwise unavailable. Yet, survival advantage does not wholly explain the reasons for human cooperative behavior. In fact, humans are motivated to cooperate even when it is not necessary to achieve an outcome. Research in cognitive science suggests that navigating the potential costs of joint actions is a challenge for humans, and that joint actions might provide individuals with rewards that go beyond the achievement of instrumental goals. We here address the influence of key factors on the decision to engage in joint action, such as the coordination costs arising when acting together compared to alone and the social and instrumental rewards expected when acting together compared to alone. Addressing these questions will provide critical insight for the design of cognitive models of human decisions for cooperation.

Social alignment matters: Following pandemic guidelines is associated with better wellbeing

BACKGROUND

In response to the Covid-19 pandemic, most countries implemented physical distancing measures. Many mental health experts warned that through increasing social isolation and anxiety, these measures could negatively affect psychosocial wellbeing. However, socially aligning with others by adhering to these measures may also be beneficial for wellbeing.

METHODS

We examined these two contrasting hypotheses using cross-national survey data (N = 6675) collected fortnightly from participants in 115 countries over 3 months at the beginning of the pandemic. Participants reported their wellbeing, perceptions of how vulnerable they were to Covid-19 (i.e., high risk of infection) and how much they, and others in their social circle and country, were adhering to the distancing measures.

RESULTS

Linear mixed-effects models showed that being a woman, having lower educational attainment, living alone and perceived high vulnerability to Covid-19 were risk factors for poorer wellbeing. Being young (18-25) was associated with lower wellbeing, but longitudinal analyses showed that young people's wellbeing improved over 3 months. In contrast to widespread views that physical distancing measures negatively affect wellbeing, results showed that following the guidelines was positively associated with wellbeing even for people in high-risk groups.

CONCLUSIONS

These findings provide an important counterpart to the idea that pandemic containment measures such as physical distancing negatively impacted wellbeing unequivocally. Despite the overall burden of the pandemic on psychosocial wellbeing, social alignment with others can still contribute to positive wellbeing. The pandemic has manifested our propensity to adapt to challenges, particularly highlighting how social alignment can forge resilience.

Stage 2 Registered Report: How responsibility attributions to self and others relate to outcome ownership in group decisions

Background: Responsibility judgements have important consequences in human society. Previous research focused on how someone's responsibility determines the outcome they deserve, for example, whether they are rewarded or punished. Here, in a pre-registered study (Stage 1 Registered Report: https://doi.org/10.12688/wellcomeopenres.16480.2), we investigate the opposite link: How outcome ownership influences responsibility attributions in a social context.  Methods: In an online study, participants in a group of three perform a majority vote decision-making task between gambles that can lead to a reward or no reward. Only one group member receives the outcome and participants evaluate their and the other players' responsibility for the obtained outcome. Results: We found that outcome ownership increases responsibility attributions even when the control over an outcome is similar. Moreover, ownership had an effect on the valence bias: participants' higher responsibility attributions for positive vs negative outcomes was stronger for players who received the outcome. Finally, this effect was more pronounced when people rated their own responsibility as compared to when they were rating another's player responsibility. Conclusions: The findings of this study reveal how credit attributions can be biased toward particular individuals who receive outcomes as a result of collective work, both when people judge their own and someone else's responsibility.

Bioethics and COVID-19: Considering the Social Determinants of Health

In this paper, we focus on a novel bioethical approach concerning the ethical implications of the Social Determinants of Health (SDs) in the time of COVID-19, offering a fresh interpretation of our agency and responsibility in the current pandemic era. Our interpretation is grounded on the idea that our health basically depends on factors that go beyond our organism. In this sense, we stress the radical importance of circumstances to ethically assess an action, in the current pandemic context. Moreover, due the centrality of the SDs in our bioethical assessments-that implies that our health does not exclusively depend on our choices, behaviors, and lifestyle-we can affirm that we are not entirely responsible for our wellness or diseases. As health depends on economic, social, cultural, and environmental factors, we argue that the analysis of personal responsibility facing personal health status should receive further consideration. In this sense, following the "social connection model," we stress the importance of the concept of "shared responsibility" in collective decisions: if we make many decisions collectively, we are also collectively responsible of these decisions. Furthermore, to responsibly tackle the social inequalities that are the underlying cause of disparities in health outcomes, we propose two main strategies based on the Capability Approach: 1. empowering the individuals, especially the most vulnerable ones; and 2. designing preventive policies and interventions that provides an opportunity to address the disparities moving forward. This will help us going beyond the "individualistic medical ethics paradigm" and integrating our concept of health with social factors (e.g., the SDs), based on a more relational and interdependent anthropological thought.

Managing uncertainty: Physicians’ decision-making for stroke prevention for patients with atrial fibrillation and intracerebral haemorrhage

Background Stroke prevention in patients with atrial fibrillation (AF) post-intracerebral haemorrhage (ICH) is an area of clinical equipoise. Little is known about the tools and processes that physicians use to make decisions regarding anticoagulation in this high-risk patient population. Objective To explore physicians’ decision-making process regarding stroke prevention in patients with AF and a recent history of ICH. Method Qualitative study, utilising semi-structured interviews and analysed using Framework analysis. Results Twenty physicians from five European countries (Austria, France, Germany, Spain, United Kingdom) participated. The over-arching theme ‘Managing uncertainty’, addressed the process of making high-risk clinical decisions in the context of little available robust clinical evidence for best practice. Three sub-themes were identified under the umbrella theme: (1) ‘Computing the Risks’, captured the challenge of balancing the risks of ischaemic stroke with the risk of recurrent ICH in a complex patient population; (2) ‘Patient Factors’ highlighted the influence that patients’ beliefs and previous experience of stroke had on physicians’ decisions; and (3) ‘Making a Decision’ explored the process of reaching a final decision regarding initiation of OAC therapy or not. Conclusion Physicians described the process of deciding on stroke prevention in patients with AF post-ICH as ‘challenging’ due to considerable ‘clinical equipoise’. Key factors that affected decision-making was patient comorbidities, functional status, and patient willingness to engage with oral anticoagulation therapy. Shared decision-making was believed to be beneficial, but physicians believed that the ultimate responsibility to decide on stroke prevention lay with the clinician.

Distinct neurocomputational mechanisms support informational and socially normative conformity

A change of mind in response to social influence could be driven by informational conformity to increase accuracy, or by normative conformity to comply with social norms such as reciprocity. Disentangling the behavioural, cognitive, and neurobiological underpinnings of informational and normative conformity have proven elusive. Here, participants underwent fMRI while performing a perceptual task that involved both advice-taking and advice-giving to human and computer partners. The concurrent inclusion of 2 different social roles and 2 different social partners revealed distinct behavioural and neural markers for informational and normative conformity. Dorsal anterior cingulate cortex (dACC) BOLD response tracked informational conformity towards both human and computer but tracked normative conformity only when interacting with humans. A network of brain areas (dorsomedial prefrontal cortex (dmPFC) and temporoparietal junction (TPJ)) that tracked normative conformity increased their functional coupling with the dACC when interacting with humans. These findings enable differentiating the neural mechanisms by which different types of conformity shape social changes of mind.

Stage 2 Registered Report: How responsibility attributions to self and others relate to outcome ownership in group decisions

Background: Responsibility judgements have important consequences in human society. Previous research focused on how someone's responsibility determines the outcome they deserve, for example, whether they are rewarded or punished. Here, in a pre-registered study (Stage 1 Registered Report: https://doi.org/10.12688/wellcomeopenres.16480.2), we investigate the opposite link: How outcome ownership influences responsibility attributions in a social context.  Methods: In an online study, participants in a group of three perform a majority vote decision-making task between gambles that can lead to a reward or no reward. Only one group member receives the outcome and participants evaluate their and the other players' responsibility for the obtained outcome. Results: We found that outcome ownership increases responsibility attributions even when the control over an outcome is similar. Moreover, ownership had an effect on the valence bias: participants' higher responsibility attributions for positive vs negative outcomes was stronger for players who received the outcome. Finally, this effect was more pronounced when people rated their own responsibility as compared to when they were rating another's player responsibility. Conclusions: The findings of this study reveal how credit attributions can be biased toward particular individuals who receive outcomes as a result of collective work, both when people judge their own and someone else's responsibility.

Many heads are more utilitarian than one

Moral judgments have a very prominent social nature, and in everyday life, they are continually shaped by discussions with others. Psychological investigations of these judgments, however, have rarely addressed the impact of social interactions. To examine the role of social interaction on moral judgments within small groups, we had groups of 4 to 5 participants judge moral dilemmas first individually and privately, then collectively and interactively, and finally individually a second time. We employed both real-life and sacrificial moral dilemmas in which the character's action or inaction violated a moral principle to benefit the greatest number of people. Participants decided if these utilitarian decisions were morally acceptable or not. In Experiment 1, we found that collective judgments in face-to-face interactions were more utilitarian than the statistical aggregate of their members compared to both first and second individual judgments. This observation supported the hypothesis that deliberation and consensus within a group transiently reduce the emotional burden of norm violation. In Experiment 2, we tested this hypothesis more directly: measuring participants' state anxiety in addition to their moral judgments before, during, and after online interactions, we found again that collectives were more utilitarian than those of individuals and that state anxiety level was reduced during and after social interaction. The utilitarian boost in collective moral judgments is probably due to the reduction of stress in the social setting.

Who initiates punishment, who joins punishment? Disentangling types of third-party punishers by neural traits

The act of punishing unfair behavior by unaffected observers (i.e., third‐party punishment) is a crucial factor in the functioning of human societies. In everyday life, we see different types of individuals who punish. While some individuals initiate costly punishment against an unfair person independently of what other observers do (independent punishers), others condition their punishment engagement on the presence of another person who punishes (conditional punishers). Still others do not want to partake in any sort of punishment (nonpunishers). Although these distinct behavioral types have a divergent impact on human society, the sources of heterogeneity are poorly understood. We present novel laboratory evidence on the existence of these three types. We use anatomical brain characteristics in combination with stated motives to characterize these types. Findings revealed that independent punishers have larger gray matter volume in the right temporo‐parietal junction compared to conditional punishers and nonpunishers, an area involved in social cognition. Conditional punishers are characterized by larger gray matter volume in the right dorsolateral prefrontal cortex, a brain area known to be involved in behavioral control and strategic reasoning, compared to independent punishers and nonpunishers. Finally, both independent punishers and nonpunishers are characterized by larger gray matter volume in an area involved in the processing of social and monetary rewards, that is, the bilateral caudate. By using a neural trait approach, we were able to differentiate these three types clearly based on their neural signatures, allowing us to shed light on the underlying psychological mechanisms.

Task complexity moderates group synergy

Scientists and managers alike have been preoccupied with the question of whether and, if so, under what conditions groups of interacting problem solvers outperform autonomous individuals. Here we describe an experiment in which individuals and groups were evaluated on a series of tasks of varying complexity. We find that groups are as fast as the fastest individual and more efficient than the most efficient individual when the task is complex but not when the task is simple. We then precisely quantify synergistic gains and process losses associated with interacting groups, finding that the balance between the two depends on complexity. Our study has the potential to reconcile conflicting findings about group synergy in previous work.

Complexity—defined in terms of the number of components and the nature of the interdependencies between them—is clearly a relevant feature of all tasks that groups perform. Yet the role that task complexity plays in determining group performance remains poorly understood, in part because no clear language exists to express complexity in a way that allows for straightforward comparisons across tasks. Here we avoid this analytical difficulty by identifying a class of tasks for which complexity can be varied systematically while keeping all other elements of the task unchanged. We then test the effects of task complexity in a preregistered two-phase experiment in which 1,200 individuals were evaluated on a series of tasks of varying complexity (phase 1) and then randomly assigned to solve similar tasks either in interacting groups or as independent individuals (phase 2). We find that interacting groups are as fast as the fastest individual and more efficient than the most efficient individual for complex tasks but not for simpler ones. Leveraging our highly granular digital data, we define and precisely measure group process losses and synergistic gains and show that the balance between the two switches signs at intermediate values of task complexity. Finally, we find that interacting groups generate more solutions more rapidly and explore the solution space more broadly than independent problem solvers, finding higher-quality solutions than all but the highest-scoring individuals.

Pooling decisions decreases variation in response bias and accuracy

Decision makers in contexts as diverse as medical, judicial, and political decision making are known to differ substantially in response bias and accuracy, and these differences are a major factor undermining the reliability and fairness of the respective decision systems. Using theoretical modeling and empirical testing across five domains, we show that collective systems based on pooling decisions robustly overcome this important but as of now unresolved problem of experts' heterogeneity. In breast and skin cancer diagnostics and fingerprint analysis, we find that pooling the decisions of five experts reduces the variation in sensitivity among decision makers by 52%, 54%, and 41%, respectively. Similar reductions are achieved for specificity and response bias, and in other domains. Thus, although outcomes in individual decision systems are highly variable and at the mercy of individual decision makers, collective systems based on pooling decrease this variation, thereby promoting reliability, fairness, and possibly even trust.

Confidence, advice seeking and changes of mind in decision making

Humans and other animals rely on social learning strategies to guide their behaviour, especially when the task is difficult and individual learning might be costly or ineffective. Recent models of individual and group decision-making suggest that subjective confidence judgments are a prime candidate in guiding the way people seek and integrate information from social sources. The present study investigates the way people choose and use advice as a function of the confidence in their decisions, using a perceptual decision task to carefully control the quality of participants' decisions and the advice provided. The results show that reported confidence guides the search for new information in accordance with probabilistic normative models. Moreover, large inter-individual differences were found, which strongly correlated with more traditional measures of metacognition. However, the extent to which participants used the advice they received deviated from what would be expected under a Bayesian update of confidence, and instead was characterised by heuristic-like strategies of categorically ignoring vs. accepting advice provided, again with substantial individual differences apparent in the relative dominance of these strategies.

Stage 1 Registered Report: How responsibility attributions to self and others relate to outcome ownership in group decisions

Responsibility judgements have important consequences in human society. Previous research focused on how someone's responsibility determines the outcome they deserve, for example, whether they are rewarded or punished. Here, we investigate the opposite link: How outcome ownership influences responsibility attributions in a social context. Participants in a group of three perform a majority vote decision-making task between gambles that can lead to a reward or no reward. Only one group member receives the outcome and participants evaluate their and the other players' responsibility for the obtained outcome. Two hypotheses are tested: 1) Whether outcome ownership increases responsibility attributions even when the control over an outcome is similar. 2) Whether people's tendency to attribute higher responsibility for positive vs negative outcomes will be stronger for players who received the outcome. The findings of this study may help reveal how credit attributions can be biased toward particular individuals who receive outcomes as a result of collective work.

Stage 1 Registered Report: How responsibility attributions to self and others relate to outcome ownership in group decisions

Responsibility judgements have important consequences in human society. Previous research focused on how someone's responsibility determines the outcome they deserve, for example, whether they are rewarded or punished. Here, we investigate the opposite link: How outcome ownership influences responsibility attributions in a social context. Participants in a group of three perform a majority vote decision-making task between gambles that can lead to a reward or no reward. Only one group member receives the outcome and participants evaluate their and the other players' responsibility for the obtained outcome. Two hypotheses are tested: 1) Whether outcome ownership increases responsibility attributions even when the control over an outcome is similar. 2) Whether people's tendency to attribute higher responsibility for positive vs negative outcomes will be stronger for players who received the outcome. The findings of this study may help reveal how credit attributions can be biased toward particular individuals who receive outcomes as a result of collective work.

Changes of Causal Attribution by a Co-actor in Situations of Obvious Causality

In social contexts, people are responsible for their actions and outcomes. Diffusion of responsibility is a well-known social phenomenon: people feel less responsible when performing an action with co-actors than when acting alone. In previous studies, co-actors reduced the participant’s responsibility attribution by making the cause of the outcomes ambiguous. Meanwhile, it is unclear whether the presence of co-actors creates diffusion of responsibility even in situations where it is “obvious” that both oneself and the co-actor are the causes of an outcome. To investigate this potential diffusion of responsibility, we used a temporal binding (TB) task as a measure of causal attribution. Low TB effects indicate the enhancement of external attribution (i.e., diffusion of responsibility) in perceptual processing for the action and outcomes. To investigate the influence of presence of a co-actor on causal attribution, participants were required to act under two experimental conditions: an ALONE condition (participant only) or a TOGETHER condition (with a co-actor). The only difference between the two conditions was whether the actions were shared. In addition, to make participants feel responsible, they were induced to feel guilt. In the High-harm condition, participants gave a financial reduction to a third party. When guilt was induced, participants showed lower TB effects in the TOGETHER condition compared to the ALONE condition. Our study suggests that actions with a co-actor change causal attributions even though the causes of the outcome are obvious. This may have implications for understanding diffusion of responsibility in inhumane situations.

Wearing a face mask against Covid-19 results in a reduction of social distancing

In the context of the Covid-19 pandemic, barrier gestures such as regular hand-washing, social distancing, and wearing a face mask are highly recommended. Critically, interpersonal distance (IPD) depends on the affective dimension of social interaction, which might be affected by the current Covid-19 context. In the present internet-based experimental study, we analyzed the preferred IPD of 457 French participants when facing human-like characters that were either wearing a face mask or displaying a neutral, happy or angry facial expression. Results showed that IPD was significantly reduced when characters were wearing a face mask, as they were perceived as more trustworthy compared to the other conditions. Importantly, IPD was even more reduced in participants infected with Covid-19 or living in low-risk areas, while it was not affected by the predicted health of the characters. These findings shed further light on the psychological factors that motivate IPD adjustments, in particular when facing a collective threat. They are also of crucial importance for policy makers as they reveal that despite the indisputable value of wearing a face mask in the current pandemic context, their use should be accompanied by an emphasis on social distancing to prevent detrimental health consequences.

Maximizing as satisficing: On pattern matching and probability maximizing in groups and individuals

Distinguishing meaningful structure from unpredictable randomness is a key challenge in many domains of life. We examined whether collaborating three-person groups (n = 81) outperform individuals (n = 81) in facing this challenge with a two-part repeated choice task, where outcomes were either serially independent (probabilistic part) or fixed in a particular sequence (pattern part). Groups performed as well as the best individuals in the probabilistic part but groups' accuracy did not credibly exceed that of the average individual in the pattern part. Qualitative coding of group discussion data revealed that failures to identify existing patterns were related to groups accepting probability maximizing as a "good enough" strategy rather than expending effort to search for patterns. These results suggest that probability maximizing can arise via two routes: recognizing that probabilistic processes cannot be outdone (maximizing as optimizing) or settling for an imperfect but easily implementable strategy (maximizing as satisficing).

The effects of recursive communication dynamics on belief updating

Many social interactions are characterized by dynamic interplay, such that individuals exert reciprocal influence over each other's behaviours and beliefs. The present study investigated how the dynamics of reciprocal influence affect individual beliefs in a social context, over and above the information communicated in an interaction. To this end, we developed a simple social decision-making paradigm in which two people are asked to make perceptual judgments while receiving information about each other's decisions. In a Static condition, information about the partner only conveyed their initial, independent judgment. However, in a Dynamic condition, each individual saw the evolving belief of their partner as they learnt about and responded to the individual's own judgment. The results indicated that in both conditions, the majority of confidence adjustments were characterized by an abrupt change followed by smaller adjustments around an equilibrium, and that participants' confidence was used to arbitrate conflict (although deviating from Bayesian norm). Crucially, recursive interaction had systematic effects on belief change relative to the static baseline, magnifying confidence change when partners agreed and reducing confidence change when they disagreed. These findings indicate that during dynamic interactions-often a characteristic of real-life and online social contexts-information is collectively transformed rather than acted upon by individuals in isolation. Consequently, the output of social events is not only influenced by what the dyad knows but also by predictable recursive and self-reinforcing dynamics.

Collective intelligence in fingerprint analysis

When a fingerprint is located at a crime scene, a human examiner is counted upon to manually compare this print to those stored in a database. Several experiments have now shown that these professional analysts are highly accurate, but not infallible, much like other fields that involve high-stakes decision-making. One method to offset mistakes in these safety-critical domains is to distribute these important decisions to groups of raters who independently assess the same information. This redundancy in the system allows it to continue operating effectively even in the face of rare and random errors. Here, we extend this "wisdom of crowds" approach to fingerprint analysis by comparing the performance of individuals to crowds of professional analysts. We replicate the previous findings that individual experts greatly outperform individual novices, particularly in their false-positive rate, but they do make mistakes. When we pool the decisions of small groups of experts by selecting the decision of the majority, however, their false-positive rate decreases by up to 8% and their false-negative rate decreases by up to 12%. Pooling the decisions of novices results in a similar drop in false negatives, but increases their false-positive rate by up to 11%. Aggregating people's judgements by selecting the majority decision performs better than selecting the decision of the most confident or the most experienced rater. Our results show that combining independent judgements from small groups of fingerprint analysts can improve their performance and prevent these mistakes from entering courts.

Joining a group diverts regret and responsibility away from the individual

It has recently been proposed that a key motivation for joining groups is the protection from the negative consequences of undesirable outcomes. To test this claim, we investigated how experienced outcomes triggering loss and regret impacted people's tendency to decide alone or join a group, and how decisions differed when voluntarily made alone versus in group. Replicated across two experiments, participants (n = 125 and n = 496) selected whether to play alone or contribute their vote to a group decision. Next, they chose between two lotteries with different probabilities of winning and losing. The higher the negative outcome, the more participants switched from deciding alone to with others. When joining a group to choose the lottery, choices were less driven by outcome and regret anticipation. Moreover, negative outcomes experienced alone, not part of a group vote, led to worse subsequent choices than positive outcomes. These results suggest that the protective shield of the collective reduces the influence of negative emotions that may help individuals re-evaluate past choices.

Punishing the individual or the group for norm violation

Background: It has recently been proposed that a key motivation for joining groups is the protection from consequences of negative behaviours, such as norm violations. Here we empirically test this claim by investigating whether cooperative decisions and the punishment of associated fairness-based norm violations are different in individuals vs. collectives in economic games. Methods: In the ultimatum game, participants made or received offers that they could reject at a cost to their outcome, a form of social punishment. In the dictator game with third-party punishment, participants made offers to a receiver while being observed by a punisher, or could themselves punish unfair offers. Results: Participants made lower offers when making their decision as part of a group as compared to alone. This difference correlated with participants' overall mean offers: those who were generally less generous were even less so in a group, suggesting that the collective structure was compatible with their intention. Participants were slower when punishing vs not punishing an unfair offer. Importantly here, they were slower when deciding whether to punish or not to punish groups as compared to individuals, only when the offer concerned them directly in second party punishment. Participants thus take more time to punish others, and to make their mind on whether to punish or not when facing a group of proposers. Conclusions: Together, these results show that people behave differently in a group, both in their willingness to share with others and in their punishment of norm violations. This could be explained by the fact that being in a collective structure allows to share responsibility with others, thereby protecting from negative consequences of norm violations.

Punishing the individual or the group for norm violation

Background: It has recently been proposed that a key motivation for joining groups is the protection from consequences of negative behaviours, such as norm violations. Here we empirically test this claim by investigating whether cooperative decisions and the punishment of associated fairness-based norm violations are different in individuals vs. collectives in economic games. Methods: In the ultimatum game, participants made or received offers that they could reject at a cost to their outcome, a form of social punishment. In the dictator game with third-party punishment, participants made offers to a receiver while being observed by a punisher, or could themselves punish unfair offers. Results: Participants made lower offers when making a collective rather than an individual decision. This difference correlated with participants' overall mean offers: those who were generally less generous were even less so in a group, suggesting that the collective structure was compatible with their intention. Participants were slower when punishing vs not punishing an unfair offer. Importantly here, they were slower when deciding whether to punish groups as compared to individuals, only when the offer concerned them directly in second party punishment. Participants thus seem reluctant to punish others, and even more so when facing a group of proposers. Conclusions: Together, these results show that people behave differently in a group, both in their willingness to share with others and in their punishment of norm violations. This could be explained by the fact that being in a collective structure allows to share responsibility with others, thereby protecting from negative consequences of norm violations.