The Bystander Effect: Reactions and Causes

Bystander Effect:The Bystander Effect Reactions and Causes

The bystander effect is an element of social psychology that implies that when the number of bystanders is increased in an emergency situation, the less likely any of the bystanders will aid, or assist in the situation (Aronson, Wilson, & Akert, 2013). The bystander effect is one of the most significant well established social psychology findings, which manifested in the late 1960’s (Levine & Crowther, 2013). The cause for social psychologist to begin to study how bystanders react during emergency situations, was due to Kitty Genovese being attacked and murdered in front of her Queens, New York apartment in 1964 (Aronson et al., 2013). Kitty’s unfortunate attack lasted nearly 45 minutes and was witnessed by nearly 38 residents who did not assist by calling police, or trying to stop her attacker (Aronson et al., 2013). Kitty’s death, along with social psychologists research established not only the bystander effect, but other elements that are related to the reasons why the bystander effect occurs in groups of bystanders. The causes are significant to the explanation of the bystander effect and implore different elements in their explanation and relativity. The bystander effect contains different components related to the assistance of the bystanders helping behavior, as well as different social and cultural manifestations and their relevant causes.

Diffusion of Responsibility and Pluralistic Ignorance One of the main reasons why the bystander effect occurs is due to a social influence being present known as diffusion of responsibility (Heroic Imagination Project, 2013). The diffusion of responsibility is a phenomenon related to the bystander’s sense of responsibility to aid and decreases when there are more witnesses present (Aronson et al., 2013). Diffusion of responsibility simple implies that bystanders do not react because they feel that other bystanders will respond to the emergency situation and render appropriate assistance (Schwartz, & Gottlieb, 1976). This phenomenon only requires one bystander and increases in larger groups and decreases in smaller groups.

Pluralistic Ignorance relates to helping behavior, as well as to pluralistic ignorance being present when bystanders think that others are interpreting the incident in a certain way, when indeed they are not (Aronson et al., 2013). This thought comes into notion as bystanders witness a situation, then base their reaction to the incident by gaging other onlookers responses to the incident. If the bystander sees others reacting a certain way, then they too will be more apt to express their thought of the incident as not being too big of an issue, thus effecting their helping influences.

Knowing How to Help When a bystander has decided to help, they must decide what kind of help is appropriate for the situation (Aronson et al., 2013). Rendering assistance also incorporates decision implementation factors that should be determined based upon the needs of the situation and if the bystander is qualified to provide proper assistance (Aronson et al., 2013). For example, if somebody collapses and a bystander does not know CPR, but decides to assist, they should probably assist by calling for emergency services and trying to find another bystander that can provide CPR. Often time’s bystanders will not assist because they are afraid they might make matters worse, or place themselves in danger if the situation is considered dangerous (Aronson et al., 2013). A study by Peter Fischer and Tobias Greitmeyer (2013) showed that in some circumstances, an additional bystander can increase individual intervention in situations where the person helping might expect negative consequences, but does not have the same effect when bystanders do not have a positive effect in situations involving low negative consequences (Fischer & Greitmeyer, 2013).

Cultural Differences of Helping Behavior and The Bystander Effect

Some social psychologist believe the phenomenon of the bystander has little impact and will lead to the same affects regardless of the culture. However, some studies have analyzed that culture can play a significant role in determining if a bystander will or will not assist during certain situations. Meta-analysis data show that individualist societies contain loose bonds between individuals, causing individuals to have the notion to look for themselves causing an independence reward (Pozzoli, Ang, & Gini, 2012). This differs from non-individualist societies, because non-individualist societies have been shown to contain a closer community bond, thus causing an increase in bystanders and their wiliness to help during a certain situations (Pozzoli et al., 2012). Cultural differences and helping behavior can also contain social categories that cause a higher chance for individuals to intervene (Levine & Crowther, 2013). When a group of bystanders are part of shared social category of membership, they will have an increased chance of one of them intervening if both groups contain specific norms associated with their group (Levine & Crowther, 2013). However, despite the increase chance of assistance, group size can still affect intervention (Levine & Crowther, 2013).

Conclusion The bystander effect is a unique phenomenon related to social psychology that contains many different components related to the influencing of helping behavior. Since the bystander effects emergence, it has become one of the most prolific forms of social psychology and appears in nearly all social psychology undergraduate textbooks (Levine & Crowther, 2013). The bystander effect contains elements that ultimately provide plausible reasons as to why some choose to help or ignore certain situations. Typically, ones decision to assist is impacted heavily by diffusion of responsibility and other aspects of knowing when and if to help. Other components, like cultural differences and social situations can also determine the outcome, based on group size and the totality of the circumstance.


Aronson, E., Wilson, T., &Akert,R. (2013). Social Psychology (8th ed.). Upper Saddle, New Jersey:Pearson Education Inc.

Fischer, P., & Greitemeyer, T. (2013). The Positive Bystander Effect: Passive Bystanders Increase Helping in Situations With High Expected Negative Consequences for the Helper. Journal Of Social Psychology, 153(1), 1-5. doi:10.1080/00224545.2012.697931

Heroic Imagination Project. (2013). Bystander Effect and Diffusion of Responsibility. Retrieved from

Levine, M., & Crowther, S. (2008). 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), 1429-1439. doi:10.1037/a0012634

Pozzoli, T., Ang, R. P., & Gini, G. (2012). Bystanders’ Reactions to Bullying: A Cross-cultural Analysis of Personal Correlates Among Italian and Singaporean Students. Social Development, 21(4), 686-703. doi:10.1111/j.1467-9507.2011.00651.x Schwartz, S. H., & Gottlieb, A. (1976). Bystander reactions to a violent theft: Crime in Jerusalem. Journal Of Personality And Social Psychology, 34(6), 1188-1199. doi:10.1037/0022-3514.34.6.1188

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