Heiko Rauhut

How social influence can undermine the wisdom of crowd effect

Social groups can be remarkably smart and knowledgeable when their averaged judgements are compared with the judgements of individuals. Already Galton [Galton F (1907) Nature 75:7] found evidence that the median estimate of a group can be more accurate than estimates of experts. This wisdom of crowd effect was recently supported by examples from stock markets, political elections, and quiz shows [Surowiecki J (2004) The Wisdom of Crowds]. In contrast, we demonstrate by experimental evidence (N = 144) that even mild social influence can undermine the wisdom of crowd effect in simple estimation tasks. In the experiment, subjects could reconsider their response to factual questions after having received average or full information of the responses of other subjects. We compare subjects’ convergence of estimates and improvements in accuracy over five consecutive estimation periods with a control condition, in which no information about others’ responses was provided. Although groups are initially “wise,” knowledge about estimates of others narrows the diversity of opinions to such an extent that it undermines the wisdom of crowd effect in three different ways. The “social influence effect” diminishes the diversity of the crowd without improvements of its collective error. The “range reduction effect” moves the position of the truth to peripheral regions of the range of estimates so that the crowd becomes less reliable in providing expertise for external observers. The “confidence effect” boosts individuals’ confidence after convergence of their estimates despite lack of improved accuracy. Examples of the revealed mechanism range from misled elites to the recent global financial crisis.

Self-Organization and Emergence in Social Systems: Modeling the Coevolution of Social Environments and Cooperative Behavior

We demonstrate with computational simulation scenarios how social environments and individual behavior coevolve and how fundamentally different macro-effects emerge, when separate micromechanisms are combined. Our framework considers social interactions among agents on a spatial grid or in networks. In the Prisoners Dilemma, neither imitation of more successful strategies nor the migration to more favorable locations can promote cooperation. However, when both microscopic mechanisms are combined, they cause the segregation of cooperators and defectors, and the self-organization of cooperative clusters on the macro-level. These are robust to randomness, while cooperation may break down in a “globalized society.” The implications for the evolution of norms and institutions are discussed.

Higher Punishment, Less Control?

Rational choice theory predicts for higher punishment less crime. However, many field studies could not support this conclusion. A game theoretic approach can explain these puzzling findings because it takes not only criminals but also control agents rationality into account. Mixed Nash equilibria predict for higher punishment less control and no effect on crime rates. A new experimental design is introduced to test game theoretic hypotheses. 196 subjects have been partitioned into `inspectees who can steal money from each other and `inspectors who can invest in control activities to catch inspectees. Static and dynamic analyses show that strategic interaction plays an important role for crime and punishment. However, effects are not as strong as predicted. Higher punishment indeed causes less control, but crime is deterred as well. Furthermore, dynamical analyses with the learning model fictitious play reveal that humans learn only slowly in inspection situations.

Lifting the veil of ignorance : An experiment on the contagiousness of norm violations

Norm violations can be contagious. Previous research analyzed two mechanisms of why knowledge about others’ norm violations triggers its spread: (1) actors lower their subjective beliefs about the probability or severity of punishment or (2) they condition their compliance on others’ compliance. While earlier field studies could hardly disentangle both effects, we use a laboratory experiment which eliminates any punishment threat. Subjects (nu2009=u2009466) can throw a die and are paid according to their reported number. Our design rules out any possibility of personal identification so that subjects can lie about their thrown number and claim inflated payoffs without risking detection. The aggregate distribution of reported payoffs allows the estimation of the extent to which the honesty norm is violated. We compare two treatment conditions in which subjects are informed about lying behavior of others with a control condition without information feedback. Observations from a subsequent die throw reveal that knowledge about liars triggers the spread of lying compared to the control condition. Results from a follow-up experiment show that this effect is moderated by subjects’ beliefs about the prevalence of norm violations of others. Our results demonstrate the contagiousness of norm violations, where actors imitate norm violations of others under the exclusion of strategic motives.

Die Durchsetzung sozialer Normen in Low-Cost und High-Cost Situationen Enforcement of Social Norms in Low-Cost and High-Cost Situations

Zusammenfassung In Feldstudien konnte häufig mittels der Low-Cost Hypothese gezeigt werden, dass normkonformes Verhalten von den dafür aufzuwendenden Kosten abhängt. Doch die Gültigkeit der Low-Cost Hypothese ist bei der Durchsetzung sozialer Normen bislang wenig erforscht. In unserer Studie werden diese kollektiven Güter zweiter Ordnung anhand nachbarschaftlicher Kontrollen analysiert. Es werden Daten einer postalischen Befragung von 631 Personen in Leipzig aus dem Jahr 2001 ausgewertet. Der Zusammenhang zwischen der Befürwortung sozialer Kontrollen und der Bereitschaft, soziale Kontrollen zu dulden, sinkt mit steigenden Kosten der zu duldenden Kontrollen. Zudem lässt sich die Logik der Low-Cost Hypothese auf andere soziologische Konstrukte übertragen: Die Wirkung von Kriminalitätsfurcht und Autoritarismus ist umso weniger relevant für die Duldung sozialer Kontrollen, je höher die Kosten dafür werden. Unsere Befunde demonstrieren somit die Gültigkeit der Low-Cost Hypothese im Zusammenhang mit kollektiven Gütern zweiter Ordnung. Summary Field studies show that normative behavior depends on the costs of obeying the norm. This effect is known as the low-cost hypothesis. However, does the enforcement of social norms also depend on the costs of enforcing the norm? So far, there has been little research on the validity of the low-cost hypothesis for these so-called “second order collective goods.” In our work, enforcement of social norms is studied by means of analyzing social control in neighborhoods. We use data from 631 respondents in a mail survey conducted in 2001 in Leipzig, Germany. Logistic regression models reveal that the strength of the relationship between the general approval of social control and the willingness to tolerate social control personally decreases with the increasing costs of tolerating these control activities. In addition, we transfer the logic of the low-cost hypothesis to other sociological constructs: The effect of fear of crime and the effect of authoritarianism on the tolerance of social control decreases with the increasing costs of these control activities. Our empirical findings confirm the low-cost hypothesis for the production of second-order collective goods.

Beliefs about Lying and Spreading of Dishonesty: Undetected Lies and Their Constructive and Destructive Social Dynamics in Dice Experiments

Field experiments have shown that observing other people littering, stealing or lying can trigger own misconduct, leading to a decay of social order. However, a large extent of norm violations goes undetected. Hence, the direction of the dynamics crucially depends on actors beliefs regarding undetected transgressions. Because undetected transgressions are hardly measureable in the field, a laboratory experiment was developed, where the complete prevalence of norm violations, subjective beliefs about them, and their behavioral dynamics is measurable. In the experiment, subjects could lie about their monetary payoffs, estimate the extent of liars in their group and make subsequent lies contingent on information about other peoples lies. Results show that informed people who underestimate others lying increase own lying more than twice and those who overestimate, decrease it by more than half compared to people without information about others lies. This substantial interaction puts previous results into perspective, showing that information about others transgressions can trigger dynamics in both directions: the spreading of normative decay and restoring of norm adherence.

Does ignorance promote norm compliance

A large extent of undetected norm violations may have positive effects for society. If many norm violations are hidden, society seems to be in good order so that actors are more willing to comply with the norms themselves. In this sense, ignorance promotes norm compliance. We challenge this view by arguing that in scenarios, in which norms are controlled and enforced by third parties who receive rewards for their success, the opposite is true: Ignorance promotes norm violations. The reason is that unsuspicious inspectors who believe that little hidden norm violations are committed will spend less effort for detection, some formerly detected norm violations will go undetected, norm targets will be less deterred from the lower detection probability and will commit more norm violations over time. This article develops a respective mathematical model and confirms the above described intuition.

Conditions for the Emergence of Shared Norms in Populations with Incompatible Preferences

Understanding norms is a key challenge in sociology. Nevertheless, there is a lack of dynamical models explaining how one of several possible behaviors is established as a norm and under what conditions. Analysing an agent-based model, we identify interesting parameter dependencies that imply when two behaviors will coexist or when a shared norm will emerge in a heterogeneous society, where different populations have incompatible preferences. Our model highlights the importance of randomness, spatial interactions, non-linear dynamics, and self-organization. It can also explain the emergence of unpopular norms that do not maximize the collective benefit. Furthermore, we compare behavior-based with preference-based punishment and find interesting results concerning hypocritical punishment. Strikingly, pressuring others to perform the same public behavior as oneself is more effective in promoting norms than pressuring others to meet one’s own private preference. Finally, we show that adaptive group pressure exerted by randomly occuring, local majorities may create norms under conditions where different behaviors would normally coexist.

Majoritarian democracy undermines truth-finding in deliberative committees

The median of independent judgments usually outperforms most individual estimates of vaguely known facts. This wisdom-of-crowd phenomenon emerges from largely dispersed individual estimates whose aggregate is typically less biased than the average individual. Since democracy is to aggregate peoples diverse preferences and judgments, it is crucial to identify voting rules promoting the wisdom of crowds. While the median voter theorem favors the majority rule, the theory of deliberative democracy highlights the importance of opinion exchange and revision of judgments. We show experimentally, however, that a combination of majority rule and deliberation worsens collective judgments compared to deliberation under unanimity or no decision rule even without conflicting interests among discussants. Thus, the truth-finding competence of committees is significantly weakened by the majority rule.

Die Präventivwirkung des Nichtwissens im Experiment / Experimental Evidence for the Preventive Effect of Ignorance

Zusammenfassung „Die Präventivwirkung des Nichtwissens“ ist eine Hypothese über die Stabilität des Normensystems, die von Heinrich Popitz (1968) aufgestellt wurde. Die Hypothese schreibt der Dunkelziffer eine normstabilisierende Kraft zu. Würde demnach das tatsächliche Ausmaß von Normabweichungen bekannt, müsste dies das Normensystem schwächen. Bei Ahndung aller Normenbrüche würde das Normensystem kollabieren. Wir untersuchen mit einem einfachen Experiment, inwieweit die Aufdeckung der Dunkelziffer tatsächlich zu einer Erhöhung normverletzenden Verhaltens führt. Summary “The preventive effect of ignorance” is a hypothesis about the stability of norms suggested by Heinrich Popitz (1968). This hypothesis claims that the numbers of unknown cases causes norm compliance. Thus, if the actual extent of norm violations were known, the normative system would deteriorate. If all norm violations were sanctioned, the normative system would collapse. By means of a simple laboratory experiment, we investigate whether the revelation of the dark figure actually triggers an increasing rate of norm violations