H. Elffers

Intervene to be Seen: The Power of a Camera in Attenuating the Bystander Effect

Security cameras became such a part of everyday life that their presence may escape from our conscious attention. The present research examines the impact of cameras on intervening in crime, a situation in which the classic bystander effect has been uncovered. In our experimental set up, participants witnessed how another participant (a confederate) stole money, in the presence of either two or no other bystanders. Moreover, we used a security camera to make people feel watched. We expected to replicate the bystander effect without security camera’s presence and an attenuation of the bystander effect with a security camera present. As expected, the findings revealed that without a camera, participants were less likely to stop our confederate from stealing money when other bystanders were present. However, when there was a camera present this effect was attenuated: The camera increased intervention when people are otherwise least likely to help—when other bystanders are present.

The discrepancy between survey-based victim accounts and police reports revisited

This article investigates the discrepancy between victimization surveys and police data, or the extent to which crimes that are reported in one source can be traced back to the other. We used traditional reverse and forward record checks to investigate reciprocal validity. In addition, we designed a new, more comprehensive measure that is more optimally geared towards calculating the total discrepancy between the two data sources. We used victimization surveys and police data from Amsterdam, The Netherlands. Results of the reverse record check showed that in 48% of cases a survey respondent did not mention victimization, even though it appeared in police registration. Results of the forward record check showed that only 35% of reported victimization in the survey could be traced back to police data within the reference period. Forward telescoping occurred in 28% of cases. In 7% of cases, respondents reported victimization experienced by household members. Furthermore, 29% of victimization reported to the police according to survey respondents could not be traced back to police data. Finally, we calculated the total discrepancy between the police data and the victimization survey and found that reports of 18% of respondents in the victimization survey were not congruent with the police data.

The Influence of New Technologies on the Visual Attention of CSIs Performing a Crime Scene Investigation.

Currently, a series of promising new tools are under development that will enable crime scene investigators (CSIs) to analyze traces in situ during the crime scene investigation or enable them to detect blood and provide information on the age of blood. An experiment is conducted with thirty CSIs investigating a violent robbery at a mock crime scene to study the influence of such technologies on the perception and interpretation of traces during the first phase of the investigation. Results show that in their search for traces, CSIs are not directed by the availability of technologies, which is a reassuring finding. Qualitative findings suggest that CSIs are generally more focused on analyzing perpetrator traces than on reconstructing the event. A focus on perpetrator traces might become a risk when other crime‐related traces are overlooked, and when analyzed traces are in fact not crime‐related and in consequence lead to the identification of innocent suspects.

The lonely bystander: ostracism leads to less helping in virtual bystander situations

Abstract People are less likely to help when they have been ostracized, or when they are in the presence of bystanders. In the current manuscript we test both these influences simultaneously. We postulated two opposing hypotheses: first, helping decreases after ostracism, even when intervention is already less likely due to bystander presence. Second, the bystander effect could be reversed, as helping may benefit one’s reputation, especially in the presence of others. After playing Cyberball to manipulate ostracism, participants could help others on either a crowded or empty internet forum. In support of the first hypothesis, we found two main effects: replicating the bystander effect, the presence of others diminished helping. Moreover, ostracism diminished helping, even in the presence of others.

Investigating Prevention by Simulation Methods

This chapter discusses the use of agent based and laboratory simulation methods for investigating preventive measures against crime. We distinguish anticipatory prevention that attempts to preclude that offenders and targets meet while no guardians are present, and mitigating prevention that when such meetings take place attempt to deflect the seriousness of crime or indeed interrupt its execution. After a brief discussion on how simulation studies can contribute to evaluation of measures, various agent based simulation studies on police strategies (anticipatory prevention) and laboratory studies on victim training (mitigating prevention) are reviewed.

Booze, Bars, and Bystander Behavior: People who Consumed Alcohol Help Faster in the Presence of Others.

People help each other less often and less quickly when bystanders are present. In this paper, we propose that alcohol consumption could attenuate or reverse this so-called bystander effect. Alcohol impairs people cognitively and perceptually, leading them to think less about the presence of others and behave less inhibited. Moreover, alcohol makes people more prone to see the benefits of helping and not the costs. To provide an initial test of these lines of reasoning, we invited visitors of bars in Amsterdam to join our study at a secluded spot at the bar. We manipulated bystander presence, and at the end of the study, we measured alcohol consumption. When participants took their seats, the experimenter dropped some items. We measured how many items were picked up and how quickly participants engaged in helping. Results revealed that alcohol did not influence the bystander effect in terms of the amount of help given. But importantly, it did influence the bystander effect in terms of response times: people who consumed alcohol actually came to aid faster in the presence of others.