David F. Urschler, Julia Fischer, Andreas Kastenmüller, Peter Fischer

Transcription

1 1 von :34 Bystander Effect David F. Urschler, Julia Fischer, Andreas Kastenmüller, Peter Fischer LAST MODIFIED: 28 JULY 2015 DOI: /OBO/ Introduction The starting point for research on the bystander effect was the brutal rape-murder of Catherine Kitty Genovese in Kitty was stabbed to death in front of her apartment in Queens, New York, while thirty-eight people in her neighborhood witnessed, for approximately forty minutes (from the safety of their apartments), this cruel event without taking either active (e.g., trying to stop the perpetrator) or passive (e.g., calling the police) action. After that tragic event, Latané and Darley developed their famous process model of help-giving. In short, their model assumes that a bystander who witnesses a crisis situation has to progress through five sequential steps before he or she will intervene (for detailed information, see the Process Model of Help-Giving). Latané and Darley argued that the witnesses failed to intervene because there were too many of them. Therefore, the bystander effect is defined by an increased likelihood that individuals are less willing to intervene in critical situations the more other passive people are present. Compare the following situation with Kitty s case. In 2001, a group of young right-wing skinheads chased a young Greek man in Munich, Germany. Subsequently, they caught him and brutally beat him. Again, several individuals witnessed this case of emergency, yet only one young man from Turkey decided to take action. He pulled the blood-stained victim aside and saved his life by risking his own. These examples give rise to the question: what factors influence bystanders to intervene in such situations or not to intervene? Since the 1960s many studies have been conducted to answer this question. One of the most common and influential factors that affects the willingness of bystanders to help is the number of individuals (the so-called bystanders) witnessing a case of emergency. Most classic studies have shown that the greater the number of bystanders, the less helping behavior is exhibited. However, some studies have revealed contradictory findings, especially those that are more recent. This article aims to clarify these contrasting results. Specifically, influential factors (i.e., the dangerousness of an emergency) that can reduce, or even reverse, typical bystander behavior are highlighted (for detailed information, see Influencing Factors). General Overviews Griggs and Proctor 2002 affirms that the bystander effect is one of most-cited effects in introductory psychology textbooks. Thus, almost any general introductory psychology textbook covers the bystander effect. The chapter on social psychology in Gerrig and Zimbardo 2008 provides a brief overview that gives the reader a first impression concerning the basic mechanisms behind the bystander effect. Almost all introductory textbooks in the field of social psychology cover the bystander effect. A good overview of the bystander effect (including historical and up-to-date findings) can be found in the chapter on prosocial behavior in Aronson, et al. 2012, a volume for undergraduate students in social psychology. The chapter on prosocial behavior in Fletcher and Clark 2003 provides a good introduction to the bystander effect. Aronson, Elliot, Timothy D. Wilson, and Robin M. Akert Social psychology. 8th ed. Harlow, UK: Pearson/Education. This text for undergraduate students covers the most important theories and phenomena in the field of social psychology. Includes a good presentation of the bystander effect. Fletcher, Garth J. O., and Margaret S. Clark, eds Interpersonal processes. Blackwell handbook of social psychology. Malden, MA: Blackwell. This edited volume provides an excellent overview of interpersonal processes. The chapter on prosocial behavior by Dovidio and

2 2 von :34 Penner provides answers to the questions: When do people help? Why do people help? Who does help? Gerrig, Richard J., and Philip G. Zimbardo Psychology and life. 19th ed. Boston: Allyn & Bacon. This fundamental textbook provides a comprehensive overview of the most important psychological effects, including the bystander effect. All effects reviewed are connected with a student s everyday life. Therefore, this book is highly recommended for those seeking an introductory text in psychology. Griggs, Richard A., and Derrick L. Proctor A citation analysis of who s who in introductory textbooks. Teaching of Psychology 29.3: Griggs and Proctor s article provides a comprehensive overview of the most-cited authors in introductory psychology textbooks. Latané is included among these authors, thus underscoring the centrality of the bystander effect. Textbooks Latané and Darley 1970 is the fundamental textbook in the field of bystander research and, until now, it has been the only textbook that deals exclusively with the bystander effect. In addition to this groundbreaking publication, several up-to-date social psychology textbooks cover the bystander effect. Most of them are written for undergraduate students, including Aronson, et al. 2012, a widely used introductory textbook in social psychology. All textbooks treating prosocial behavior include comprehensive coverage of the bystander effect. Dovidio, et al. 2006, a highly recommended textbook, provides detailed insights into the field of prosocial behavior from a multilevel perspective. Aronson, Elliot, Timothy D. Wilson, and Robin M. Akert Social psychology. 8th ed. Harlow, UK: Pearson/Education. This text for undergraduate students covers the most important theories and phenomena in the field of social psychology. Includes a good presentation of the bystander effect. Dovidio, John F., Jane A. Piliavin, David A. Schroeder, and Louis A. Penner The social psychology of prosocial behavior. Mahwah, NJ: Erlbaum. Starting from its origins to the development of prosociality to prosocial behavior in collectives, this textbook provides an encompassing overview of psychological theories on prosocial behavior in general as well of the bystander effect. Latané, Bibb, and John M. Darley The unresponsive bystander: Why doesn t he help? New York: Appleton- Century-Croft. This fundamental textbook covers the basic theory behind the bystander effect, classic experimental studies, and it gives a detailed description of the process model of help-giving. Journals Research on the bystander effect is published in many scientific journals. Most research on the bystander effect can be found in international journals that deal with the fields of social psychology and personality. European Journal of Social Psychology, Journal of Applied Social Psychology, Journal of Experimental Social Psychology, Journal of Personality and Social Psychology, Personality and Social Psychology Bulletin, the Journal of Social Psychology, and Social Psychology.

3 3 von :34 European Journal of Social Psychology This journal publishes research articles, short papers, and reviews in all areas of social psychology (e.g., intergroup relations, group processes, social influence and persuasion) Journal of Applied Social Psychology Publishes experimental research that is applicable to social issues (e.g., safety, hazards, war, and health). Journal of Experimental Social Psychology Publishes original research and theory on human social behavior and related phenomena. It covers empirical-based research, literature reviews, theoretical analyses, and methodological comments to advance understanding of important social psychological processes. Journal of Personality and Social Psychology This top-notch journal publishes principally empirical research in all areas of personality and social psychology. The Journal of Personality and Social Psychology is divided into three independently edited sections: (a) Attitudes and Social Cognition, (b) Interpersonal Relations and Group Processes, and (c) Personality Processes and Individual Differences. Journal of Social Psychology Publishes reports on laboratory and field research in core areas of social and organizational psychology (e.g., prosocial behavior, social influence, groups and teams). Personality and Social Psychology Bulletin This top-ranked journal publishes original empirical papers in all areas of personality and social psychology. It focuses on controversial debates on well-known topics and on innovative and contemporary research. Social Psychology Publishes basic social psychological research, methodological advances in the field of social psychology, and applied research in the fields of social psychology. Social Psychology focuses on original empirical research, but it is also open for reviews and replications of published research. From Emergency to Intervention The brutal rape-murder of Catherine Kitty Genovese in 1964 led researchers into the bystander effect to focus on the question: under which conditions will bystanders intervene, and when will they not do so? Latané and Darley s process model of help-giving provides the framework in answering this question (see the Process Model of Help-Giving). Additionally, Latané and Darley described psychological processes that can lead to nonintervention (see Interrupting Psychological Processes). The Process Model of Help-Giving Latané and Darley affirm that, in the process model of help-giving, a bystander who witnesses an emergency has to progress through five sequential steps through before he or she will intervene (Latané and Darley 1970). First, a critical situation must be noticed (Step 1). After noticing the situation, the bystander will then evaluate it as an emergency or nonemergency (Step 2). If a

4 4 von :34 bystander has noticed a situation and has evaluated it as an emergency, he or she may then feel a personal sense of responsibility for taking action (Step 3: assumption of personal responsibility). If so, a bystander will then evaluate whether he or she has the appropriate skills to intervene (Step 4: perceived competencies). Finally, a conscious implementing decision will be made (Step 5: decisions to help). A bystander must pass through each and every step sequentially; otherwise, he or she will fail to help. To place the theoretical model in a real-life scenario, imagine the following situation. You are standing at a bus station and listening to music on your mp3 player. Next to you a group of male teenagers is giggling and making jokes with each another. Suddenly, two of them start to push each other. According to the model, their action means you should first recognize the situation (Step 1), even though you are perhaps listening to your favorite song on your mp3 player. If you have noticed the event, you must then interpret it as being an emergency or not (Step 2). Maybe the two young men are pushing each other for fun. If you recognize that they are not (Step 3), the question then arises whether you are personally responsible to intervene or not. Because no one else is around, you are in charge. But before intervening you must then self-evaluate (Step 4) your intervention skills (e.g., de-escalating communication strategies or physical power). Finally, you must then make the conscious decision (Step 5) to intervene or not. Latané and Darley s groundbreaking process model of help-giving has given psychology (especially social psychology) one of the most well-known and accepted theoretical constructs. It has provided the basis for hundreds of studies that have been constructed that give insight, both theoretical and practical, regarding the question of why people do not help in particular situations. Interrupting Psychological Processes Research on bystander behavior has identified three psychological processes that can interrupt the five steps in the help-giving model (see the Process Model of Help-Giving). According to Latané and Rodin 1969, the first psychological process is called pluralistic ignorance, a process that results when bystanders are faced with an ambiguous situation that could be interpreted as an emergency or not. If other bystanders demonstrate no intention to take action, then people are less likely to interpret the ambiguous situation as an emergency. According to the example mentioned under Process Model of Help-Giving, this means that if you are not sure whether the teenagers are pushing each other for fun or not, you will check the reaction of other individuals (on the assumption that more people are at the bus stop). When no one else shows a concern that the situation appears to be threatening, you are unlikely to become active. Darley and Latané 1968 and Latané and Nida 1981 label the second process diffusion of responsibility; whereby the number of bystanders present during an emergency is inversely proportional to the personal responsibility each individual bystander experiences. In other words, as the number of witnesses rises, the likelihood of any specific individual deciding to intervene falls. Referring to our example under Process Model of Help-Giving, this implies that if you are alone at the bus stop, you have a 100 percent responsibility to intervene. However, when nine others are present, you have only a 10 percent responsibility. Latané and Darley 1970 identifies a third and final process called evaluation apprehension, which stems from the fear of bystanders that acting in a public setting may potentially subject them to wide scrutiny if their behavior is deemed inadequate. Relating to our example this means that a bystander may be afraid of acting wrongly in front of others (e.g., if you are not able to solve such an easy to settle situation you will be derided). Darley, John M., and Bibb Latané Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology 8: Darley and Latané s research paper includes one of the first studies to consider the consequences of diffusion of responsibility on emergency intervention. Therefore, this is one of the most often-cited papers in the field of bystander research. Latané, Bibb, and John M. Darley The unresponsive bystander: Why doesn t he help? New York: Appleton- Century-Croft. This textbook covers all the basic theory behind the bystander effect. It includes classic experimental studies and a detailed description of the process model of help-giving. Latané, Bibb, and Steve Nida Ten years of research on group size and helping. Psychological Bulletin 89.2: The first meta-analytic review of bystander behavior conducted by two of the most well-known researchers in this field. This meta-analysis provides support for the inhibiting effect of the presence of bystanders in emergencies. However, the authors also identify boundary conditions under which the bystander effect can be weakened or eliminated.

5 5 von :34 Latané, Bibb, and Judith Rodin A lady in distress: Inhibiting effects of friends and strangers on bystander intervention. Journal of Experimental Social Psychology 5.2: This paper provides early evidence that membership of bystanders in a social category has an impact on the willingness to intervene. Influencing Factors Latané and Nida 1981 and Fischer, et al (both cited under Number of Bystanders) affirm that meta-analytical research on the bystander effect has identified several factors that determine whether a bystander will intervene. Subsections focus on the impact of the number of bystanders in a critical situation, the degree of danger in an emergency, and membership in a social category. Number of Bystanders Sources in this section focus on the issue of how bystander behavior is affected by the presence of other bystanders. The bystander effect is based on the assumption that the greater the number of passive bystanders who witness a critical situation, the less intervention will follow. This phenomenon can be observed in artificial situations (e.g., in the laboratory), in virtual reality environments, and in the field (lit). For instance, Latané and Darley 1968, shows how bystander behavior can be examined in a laboratory. Garcia, et al reveals in a series of five studies that simply imagining other bystanders reduced helping behavior in a completely unrelated task. This phenomenon is called the implicit bystander effect (for further information, see the Implicit Bystander Effect). However, as the findings in Latané and Nida 1981 and Fischer, et al indicate, the presence of other bystanders may not necessarily lead to less willingness to intervene. Based on Latané and Darley 1970, Clark and Word 1972 deals with the question whether bystander behavior is influenced by the ambiguity of a situation. Clark and Word 1972 finds that typical bystander behavior occurred in a case of ambiguous emergency but not in an unambiguous emergency. Moreover, Baumeister, et al finds that individuals who had been primed as group leaders were subsequently more willing to intervene in a staged emergency than those who had been primed as regular group members as they felt more personal responsibility and were thus less vulnerable to diffusion of responsibility. Additionally, Chekroun and Brauer 2002 affirms that people show typical bystander behavior in situations with low personal implications (e.g., preventing somebody from drawing graffiti on the walls of an elevator in a shopping mall). On the contrary, people who face a situation with high personal implications (e.g., preventing somebody from littering a neighborhood park) do not show typical bystander behavior. Baumeister, Roy F., Stuart P. Chesner, Pamela S. Senders, and Dianne M. Tice Who s in charge here? Group leaders do lend help in emergencies. Personality and Social Psychology Bulletin 14.1: This research paper provides insight into why people who were primed as group leaders, as compared to subordinate group members, do not experience as much diffusion of responsibility. Chekroun, Peggy, and Markus Brauer The bystander effect and social control behavior: The effect of the presence of others on people s reaction to norm violations. European Journal of Social Psychology 32.6: Chekroun and Brauer s three field studies point out the influencing effect of perceived personal involvement in bystander situations. Clark, Russel D., and Lerry E. Word Why don t bystanders help? Because of ambiguity? Journal of Personality and Social Psychology 24: One of the first research papers that dealt with the influencing effect of ambiguity. Clark and Word observed typical bystander behavior occurred in the ambiguous emergency but not in an unambiguous emergency. Fischer, Peter, Joachim I. Krueger, Tobias Greitemeyer, et al The bystander-effect: A meta-analytic review on bystander intervention in dangerous and non-dangerous emergencies. Psychological Bulletin 137.4:

6 6 von :34 This meta-analysis, which investigated fifty-three research articles with findings drawn from more than 7,700 participants, provides detailed information on why an increasing number of bystanders may not necessary lead to less willingness to take action. Garcia, Steven M., Kimberlee Weaver, Gordon B. Moskowitz, and John M. Darley Crowded minds: The implicit bystander effect. Journal of Personality and Social Psychology 83.4: The work of Garcia and colleagues merged the study of social contexts with bystander behavior with the result that simply imagining being surrounded by multiple people may lead to less helping behavior in an unrelated task. However, qualifying results found in Levine and Crowther 2008 (cited under Social Categorization Processes) showed that it also depends on whom you imagine and on how many of them there are. Latané, Bibb, and John M. Darley Group inhibition of bystander intervention in emergencies. Journal of Personality and Social Psychology 10: This article reviews the prototypical study setting conducted by the two pioneer researchers on the bystander effect. Latané, Bibb, and John M. Darley The unresponsive bystander: Why doesn t he help? New York: Appleton- Century-Croft. This textbook covers all the basic theory behind the bystander effect. It includes classic experimental studies and a detailed description of the process model of help-giving. Latané, Bibb, and Steve Nida Ten years of research on group size and helping. Psychological Bulletin 89.2: The first meta-analytic review of bystander behavior conducted by two of the most well-known researchers in this field. This meta-analysis provides support for the inhibiting effect of the presence of bystanders in emergencies. However, the authors also identified boundary conditions under which the bystander effect can be weakened or eliminated. The Dangerousness of an Emergency Research on bystander behavior has provided significant empirical evidence that the bystander effect is lessened or even reversed in dangerous emergencies. This section cites sources that provide explanations for this finding, one that, at first glance, could be labeled a counterintuitive phenomenon. The finds of an early laboratory experiment presented in Schwartz and Gottlieb 1976 show a reversed bystander effect, that is, individuals among a group of bystanders were more likely to intervene than individuals who witnessed the dangerous situation alone. Based on Schwarz and Gottlieb s results, the authors of Harari, et al staged a field experiment, namely, an attempted rape in a parking lot. This study again revealed that participants were more likely to intervene in this emergency when other bystanders were present. However, Schwartz and Gottlieb 1976 and Harari, et al are findings based on studies that did not directly manipulate the degree of danger of an emergency. These studies employed scenarios based on the same level of danger. For this reason a comparison of emergency situations that posed high on low danger was not possible. To solve this gap, the authors of Fischer, et al experimentally manipulated the degree of danger (high versus low) for taking action in an emergency. They found typical bystander behavior for the low danger emergency, but no effect occurred in the high danger emergency. But how can one explain this seemingly conflicting phenomenon? Fischer, et al provides three plausible explanations. First, dangerous emergencies are perceived faster and less ambiguously. This finding is in line with the results in Greitemeyer, et al and with the cost-reward model in Dovidio, et al Second, bystanders can be a source of physical support in dangerous emergencies. In particular, some situations can be resolved only by a group of people. This reasoning is in line with the results in Horowitz Third, a reduced bystander effect in dangerous cases of emergency could also be explained by a rational-choice hypothesis. Dangerous emergencies can be resolved only when bystanders cooperate and coordinate their helping response. The findings in Penner, et al provide support for this argument.

7 7 von :34 Dovidio, John F., Jane A. Piliavin, Samuel L Gaertner, David A. Schroeder, and Russell D. Clark The arousal: Cost-reward model and the process of intervention: A review of the evidence. Review of Personality and Social Psychology 12: This text provides an integrative overview of theoretical perspectives on helping behavior that is organized around the cost-reward model. Fischer, Peter, Tobias Greitemeyer, Fabian Pollozek, and Dieter Frey The unresponsive bystander: Are bystanders more responsive in dangerous emergencies? European Journal of Social Psychology 36.2: A research article that sheds light on the questions regarding why people are more willing to help in more risky situations. Additionally, it shows how to realize a well-working behavioral study. Fischer, Peter, Joachim I. Krueger, Tobias Greitemeyer, et al The bystander-effect: A meta-analytic review on bystander intervention in dangerous and non-dangerous emergencies. Psychological Bulletin 137.4: This meta-analysis, which investigated fifty-three research articles with findings drawn from more than 7,700 participants, provides detailed information as to why an increased number of bystanders may not necessarily lead to less willingness to take action. Greitemeyer, Tobias, Peter Fischer, Andreas Kastenmüller, and Dieter Frey Civil courage and helping behaviour: Differences and similarities. European Psychologist 11: This article revealed that low danger emergencies and high danger emergencies are perceived differently. High danger emergencies are perceived more quickly and are associated with enhanced perception of personal responsibility to intervene than low danger emergencies. Therefore, these findings provide an explanation as to why bystanders do not show typical bystander behavior in high danger emergencies. Harari, Herbert, Oren Harari, and Robert V. White The reaction to rape by American male bystanders. Journal of Social Psychology 125: Harari and colleagues investigated a simulated rape attempt in a realistic setting. Their results showed that individuals were more willing to help when they were members of a group of bystanders than alone. Horowitz, Irwin A The effect of group norms on bystander intervention. Journal of Social Psychology 83.2: A research article that showed that group norms can reduce bystander behavior. Penner, Louis A., John F. Dovidio, Jane A. Piliavin, and David A. Schroeder Prosocial behavior: Multilevel perspectives. Annual Review of Psychology 56: This review provides a comprehensive overview of current theory and research on prosocial behavior. It is an essential read. Schwartz, Shalom H., and Avi Gottlieb Bystander reactions to a violent theft: Crime in Jerusalem. Journal of Personality and Social Psychology 34.6: This study examines the issue of why people are more willing to help when they have the possibility of evaluation apprehension. Social Categorization Processes

8 8 von :34 Imagine the following situation: You are a big supporter of a certain soccer team. You and some friends of yours are sauntering through the city on a Saturday afternoon. You pass by a stranger who wears a shirt that sports the logo of your favorite soccer club. The stranger approaches you and asks for some change. Imagine this scenario again but replace the shirt of your favorite team with a shirt of your favorite team s greatest rival. In which of the two scenarios would you be more willing to assist the stranger? Given the presence of other bystanders, most people would be more willing to help the stranger who supports the same team. Findings on social categorization processes provide an explanation for this phenomenon. This section cites sources that deal with the influencing effect of social categorization processes on bystander behavior. Latané and Rodin 1969 indicates that bystander behavior is affected by bystanders membership in a social category. Rutkowski, et al shows that cohesiveness among bystanders could reverse the bystander effect. Levine 1999 finds that thirty-eight individuals failed to intervene in the James Bulger murder trial because they noticed that the perpetrators and the victim were family members, which means that they belonged to the same social category. However, Levine, et al shows that individuals would be more willing to help a victim if they knew that the victim was a member of the in-group. Furthermore, Levine, et al validates this effect in using a real-live emergency scenario. Levine and Crowther 2008 finds that the bystander effect was diminished when the bystanders belonged to the same social category. Taken together, the bystander effect is decreased when a potential helper and a victim belong to the same social category, and bystanders belong a social category. However, individuals show typical bystander behavior if the victim and the antagonist share a social category. For readers who are not familiar with social categorization processes, Hornsey 2008 is an excellent volume to consult before reading the sources cited in this section. Hornsey, Matthew J Social identity theory and self-categorization theory: A historical review. Social and Personality Psychology Compass 2.1: This review provides an overview of how social categorization works. Latané, Bibb, and Judith Rodin A lady in distress: Inhibiting effects of friends and strangers on bystander intervention. Journal of Experimental Social Psychology 5.2: This paper provides early evidence that membership of a bystander in a social category has an impact on the willingness to intervene. Levine, Mark Rethinking bystander nonintervention: Social categorization and the evidence of witnesses at the James Bulger murder trial. Human Relations 52.9: Testimonies of thirty-eight individuals in the James Bulger murder trial showed that their failure to intervene was primarily due to the perception that James and his murderers were brothers. This paper was one of the first to treat the role of social categorization processes in bystander research. Levine, M., Claire Cassidy, Gemma Brazier, and Stephen Reicher Self-categorization and bystander non-intervention: Two experimental studies. Journal of Applied Social Psychology 32.7: This paper sheds light on the role of social categories in bystander situations. The two experiments showed that a victim and bystanders who share the same category leads to enhanced helping behavior. Levine, Mark, and Simon Crowther The responsive bystander: How social group membership and group size can encourage as well as inhibit bystander intervention. Journal of Personality and Social Psychology 95.6: The authors present the findings from a series of four experiments that showed that bystander behavior is not a generic consequence of increasing group size. Moreover, it is also influenced by psychological relationships. Levine, Mark, Amy Prosser, David Evans, and Stephen Reicher Identity and emergency intervention: How social group membership and inclusiveness of group boundaries shape helping behavior. Personality and Social Psychology Bulletin 31.4:

9 9 von :34 This highly cited paper shows how a shared social category between a bystander and a victim can increase the likelihood of emergency intervention. Furthermore, this paper provides an example of a sophisticated experimental design to examine the impact of social categories on emergency intervention. Rutkowski, Gregory K., Charles L. Gruder, and Daniel Romer Group cohesiveness, social norms, and bystander intervention. Journal of Personality and Social Psychology 44.3: This is one of the first research papers that provides evidence that membership in a social category can lead to typical bystander behavior as well as to the increased possibility of intervening in an emergency situation. The Implicit Bystander Effect Imagine that you have just won a lottery. Your prize is a dinner for you and ten of your friends in your favorite restaurant. Now you just have to decide on which day and at what time you want to make your reservation. A few minutes after you receive this news you are asked if you would donate to charity. You decide to donate some money. Do you think that you would have donated a different sum of money if you had won a dinner for you and just one of your friends? Research on the implicit bystander effects provides answers to this question. The series of studies in Garcia, et al shows that simply thinking about a group is enough to evoke typical bystander behavior in a subsequent unrelated task (e.g., donating to charity). In addition, Garcia, et al finds that public scrutiny moderates the implicit bystander effect. As a consequence, implicit bystanders can both increase and decrease helping behavior. Levine, et al finds that the implicit bystander effect is also qualified by an implicit identity effect. For further information on the impact of identity on bystander behavior, see Social Categorization Processes. Garcia, Steven M., Kimberlee Weaver, John M. Darley, and Bryan T. Spence Dual effects of implicit bystanders: Inhibiting vs. facilitating helping behavior. Journal of Consumer Psychology 19.2: Based on the assumptions of the implicit bystander effect in Garcia, et al. 2002, this paper provides evidence that simply imagining the presence of others can increase and decrease helping behavior. Garcia, Steven M., Kimberlee Weaver, Gordon B. Moskowitz, and John M. Darley Crowded minds: The implicit bystander effect. Journal of Personality and Social Psychology 83.4: The work of Garcia and colleagues merged a focus on social contexts with bystander behavior with the result that simply imagining being surrounded by multiple people leads to less helping behavior in an unrelated task. However, there are qualifying results. Levine, et al showed that it also depends on whom you imagine and how many of them there are. Levine, Mark, Claire Cassidy, and Ines Jentzsch The implicit identity effect: Identity primes, group size, and helping. British Journal of Psychological Society 49.4: Based on the findings in Garcia, et al. 2002, this paper showed that imagining the presence of bystanders can inhibit, as well as facilitate, someone s willingness to help. This paper qualified the findings of Garcia and colleagues and revealed some boundary conditions for the implicit bystander effect. The Positive Bystander Effect Early studies of the bystander effect focused largely on the inhibiting effect of bystanders on emergency intervention. However, several studies have provided evidence that the presence of other bystanders can lead to an increased willingness to intervene in emergencies. This phenomenon is called the positive bystander effect, a result that bodes well for society. Harari, et al is one of the first studies showing that, based on the findings of a staged rape attempt, the presence of additional bystanders led to higher intervention rates. Additionally, Fischer and Greitemeyer 2013 shows that the presence of other bystanders led to an increased rate

10 10 von :34 of intervention in a simulated bike theft, when bystanders faced high negative consequences for intervening. These findings are in line with those in Fischer, et al. 2011, which found that a positive bystander effect occurs most especially in high danger emergencies. For more information about the impact of the degree of danger posed by an emergency situation on the bystander effect, see the Dangerousness of an Emergency. Furthermore, Garcia, et al provides preliminary evidence that the presence of other bystanders can facilitate helping behavior on an implicit level in situations in which the attention of a group is focused on a bystander. In line with the findings in Garcia, et al. 2009, van Bommel, et al finds that the bystander effect can be reversed in social settings with an increased public self-awareness. Fischer, Peter, and Tobias Greitemeyer The positive bystander effect: Passive bystanders increase helping in situations with high expected negative consequences for the helper. The Journal of social psychology 153:1 5. Based on the results of Fischer, et al. 2011, this field study provides further support for the positive bystander effect in situations with increased negative consequences for becoming active in situations that require intervention. Fischer, Peter, Joachim I. Krueger, Tobias Greitemeyer, et al The bystander-effect: A meta-analytic review on bystander intervention in dangerous and non-dangerous emergencies. Psychological Bulletin 137.4: This meta-analysis, which investigated fifty-three research articles with findings drawn from more than 7,700 participants, provides detailed information as to why an increased number of bystanders may not necessarily lead to less willingness to take action. Garcia, Steven M., Kimberlee Weaver, John M. Darley, and Bryan T. Spence Dual effects of implicit bystanders: Inhibiting vs. facilitating helping behavior. Journal of Consumer Psychology 19.2: Based on the assumptions concerning the implicit bystander effect made in Garcia, et al (cited under Number of Bystanders), this paper provides evidence that imagining the presence of others can increase as well as decrease helping behavior. Harari, Herbert, Oren Harari, and Robert V. White The reaction to rape by American male bystanders. The Journal of Social Psychology 125: Harari and colleagues investigated a simulated rape attempt in a realistic setting. Their results showed that individuals were more willing to help when they were members of a group of bystanders than alone. van Bommel, Marco, Jan-Willen van Prooijen, Henk Elffers, and Paul A. M. van Lange Be aware to care: Public self-awareness leads to a reversal of the bystander effect. Journal of Experimental Social Psychology 48.4: Based on the assumptions of the cost-reward model, this paper shows that the bystander effect can be reversed when bystanders perceive an increased level of public self-awareness. back to top Copyright All rights reserved.