Peer pressure (or social pressure) is the direct influence on people by peers, or an individual who gets encouraged to follow their peers by changing their attitudes, values, or behaviors to conform to those of the influencing group or individual. This type of pressure differs from general social pressure because it causes an individual to change in response to a feeling of being pressured or influenced from a peer or peer group. Social groups affected include both membership groups, in which individuals are "formally" members (such as political parties and trade unions), and cliques in which membership is not clearly defined. However, a person does not need to be a member or be seeking membership of a group to be affected by peer pressure.
There has been considerable study regarding peer pressure's effects on children and adolescents, and in popular discourse the term is mostly used in the contexts of those age groups. For children, the common themes for study regard their abilities for independent decision making; for adolescents, peer pressure's relationship with sexual intercourse and substance abuse have been significantly researched. Peer pressure can affect individuals of all ethnicities, genders, and ages, however.
Children and adolescentsEdit
Imitation plays a large role in children's lives; in order to pick up skills and techniques that they use in their own life, children are always searching for behaviors and attitudes around them that they can co-opt. Children are aware of their position in the social hierarchy from a young age: their instinct is to defer to adults' judgements and majority opinions. Similar to the Asch conformity experiments, a study done on groups of preschool children showed that they were influenced by groups of their peers to change their opinion to a demonstrably wrong one. Each child was handed a book with two sets of images on each page, with a groups of differently sized animals on the left hand page and one animal on the right hand, and each child was asked to indicate the size of the lone animal. All the books appeared the same, but the last child would sometimes get a book that was different. The children reported their size judgements in turn, and the child being tested was asked last. Before him or her, however, were a group of children working in conjunction with the researchers. Sometimes, the children who answered before the test subject all gave an answer that was incorrect. When asked in the presence of the other children, the last child's response was often the same as his or her peers. However, when allowed to privately share their responses with a researcher the children proved much more resistant to their peers' pressure, illustrating the importance of the physical presence of their peers in shaping their opinions.
An insight is that children can monitor and intervene in their peers' behavior through pressure. A study conducted in a remedial kindergarten class in the Edna A. Hill Child Development Laboratory in the University of Kansas designed a program to measure how children could ease disruptive behavior in their peers through a two-part system. After describing a series of tasks to their classroom that included bathroom usage, cleaning up, and general classroom behavior, teachers and researchers would observe children's performance on the tasks. The study focused on three children who where clearly identified as being more disruptive than their peers, and looked at their responses to potential techniques. The system utilized was a two-part one: first, each student would be given points by their teachers for correctly completing tasks with little disruption (e.g. sitting down on a mat for reading time), and if a student reached three points by the end of the day they would receive a prize. The second part brought in peer interaction, where students who reached three points were appointed "peer monitors" whose role was to lead their small groups and assign points at the end of the day. The results were clear-cut, showing that the monitored students' disruption dropped when teachers started the points system and monitored them, but when peer monitors were introduced the target students' disruption dropped to average rates of 1% for student C1, 8% for student C2, and 11% for student C3 (down from 36%, 62%, and 59%, respectively). Even small children, then, are susceptible to pressure from their peers, and that pressure can be used to effect positive change in academic and social environments.
Adolescence is the time when a person is most susceptible to peer pressure because peers become an important influence on behavior during adolescence, and peer pressure has been called a hallmark of adolescent experience. Children entering this period in life become aware for the first time of the other people around them and realize the importance of perception in their interactions. Peer conformity in young people is most pronounced with respect to style, taste, appearance, ideology, and values. Peer pressure is commonly associated with episodes of adolescent risk taking because these activities commonly occur in the company of peers. Affiliation with friends who engage in risk behaviors has been shown to be a strong predictor of an adolescent's own behavior. Peer pressure can also have positive effects when youth are pressured by their peers toward positive behavior, such as volunteering for charity  or excelling in academics. The importance of peers declines upon entering adulthood.
Even though socially accepted children often have the most opportunities and the most positive experiences, research shows that social acceptance (being in the popular crowd) may increase the likelihood of engaging in risky behavior, depending on the norms in the group. Groups of popular children showed a propensity to increase risky, drug-related and delinquent behavior when this behavior was likely to receive approval in their groups. Peer pressure was greatest among more popular children because they were the children most attuned to the judgments of their peers, making them more susceptible to group pressures. Gender also has a clear effect on the amount of peer pressure an adolescent experiences: girls report significantly higher pressures to conform to their groups in the form of clothing choices or speech patterns. Additionally, girls and boys reported facing differing amounts of pressures in different areas of their lives, perhaps reflecting a different set of values and priorities for each gender.
Peer pressure is widely recognized as a major contributor to the initiation of drug use, particularly in adolescence. This has been shown for a variety of substances, including nicotine and alcohol. While this link is well established, moderating factors do exist. For example, parental monitoring is negatively associated with substance use; yet when there is little monitoring, adolescents are more likely to succumb to peer coercion during initiation to substance use, but not during the transition from experimental to regular use. Caldwell and colleagues extended this work by finding that peer pressure was a factor leading to heightened risk in the context of social gatherings with little parental monitoring, and if the individual reported themselves as vulnerable to peer pressure. Conversely, some research has observed that peer pressure can be a protective factor against substance use.
Peer pressure produces a wide array of negative outcomes. Allen and colleagues showed that susceptibility to peer pressure in 13- and 14-year-olds was predictive of not only future response to peer pressure, but also a wider array of functioning. For example, greater depression symptomatology, decreasing popularity, more sexual behavior, and externalizing behavior were greater for more susceptible teens. Of note, substance use was also predicted by peer pressure susceptibility such that greater susceptibility was predictive of greater alcohol and drug use.
Substance use is likely not attributed to peer pressure alone. Evidence of genetic predispositions for substance use exists and some have begun to examine gene x environment interactions for peer influence. In a nationally representative sample, adolescents who had genetic predisposition were more likely to have good friends who were heavy substance users and were furthermore, more likely to be vulnerable to the adverse influence of these friends. Results from specific candidate gene studies have been mixed. For instance, in a study of nicotine use Johnson and colleagues found that peer smoking had a lower effect on nicotine dependence for those with the high risk allele (CHRNA5). This suggests that social contexts do not play the significant role in substance use initiation and maintenance as it may for others and that interventions for these individuals should be developed with genetics in mind as well.
Though the impact of peer influence in adolescence has been well established, it was unclear at what age this effect begins to diminish. It is accepted that such peer pressure to use alcohol or illicit substances is less likely to exist in elementary school and very young adolescents given the limited access and exposure. Using the Resistance to Peer Influence Scale, Sumter and colleagues found that resistance to peer pressure grew as age increased in a large study of 10- to 18-year-olds. This study also found that girls were generally more resistant to peer influence than boys, particularly at mid-adolescence (i.e. ages 13–15). The higher vulnerability to peer pressure for teenage boys makes sense given the higher rates of substance use in male teens. For girls, increased and positive parental behaviors (e.g. parental social support, consistent discipline) has been shown to be an important contributor to the ability to resist peer pressure to use substances.
Substance use prevention and intervention programs have utilized multiple techniques in order to combat the impact of peer pressure. One major technique is, naturally, peer influence resistance skills. The known correlational relationship between substance use and relationships with others that use makes resistance skills a natural treatment target. This type of training is meant to help individuals refuse participation with substance use while maintaining their membership in the peer group. Other interventions include normative education approaches (interventions designed to teach students about the true prevalence rates and acceptability of substance use), education interventions that raise awareness of potential dangers of substance use, alcohol awareness training and classroom behavior management. The literature regarding the efficacy of these approaches, however, is mixed. A study in Los Angeles and Orange Counties that established conservative norms and attempted to correct children's beliefs about substance abuse among their peers showed a statistically significant decrease in alcohol, tobacco, and marijuana use but other studies that systematically reviewed school-based attempts to prevent alcohol misuse in children found "no easily discernible pattern" in both successful and failed programs. A systematic review of intervention programs in schools conducted by Onrust et al. found that programs in elementary school were successful in slightly reducing a student's likelihood to abuse drugs or alcohol. However, this effect started to wear off with programs that targeted older students. Programs that targeted students in grades 8-9 reduced smoking, but not alcohol and other drug abuse, and programs that targeted older children reported no effect at all.
In a non-substance context, however, research has showed that decision-making training can produce concrete gains in risk perception and decision-making ability among autistic children. When administered the training in several short sessions that taught the children how to recognize risk from peers and react accordingly, the children showed through post-training assessments that they were able to identify potential threats and sources of pressure from peers and deflect them far better than normal adolescents in a control group.
Peer pressure and sexual intercourseEdit
There is evidence supporting the conclusion that parental attitudes disapproving sex tends to lead toward lower levels of adolescent unplanned pregnancy. These disparities are not due solely to parental disposition but also to communication.
A study completed in Cape Town, South Africa, looked at students at four secondary schools in the region. They found a number of unhealthy practices derived from peer pressure: condoms are derided, threats of ridicule for abstinence, and engaging in sexual activity with multiple partners as part of a status symbol (especially for males). The students colloquially call others who choose abstinence as "umqwayito", which means dried fruit/meat. An important solution for these problems is communication with adults, which the study found to be extremely lacking within adolescent social groups.
Literature reviews in this field have attempted to analyze the norms present in the interactions and decision making behind these behaviors. A review conducted by Bongardt et al. defined three types of peer norms that led to a person's participation in sexual intercourse: descriptive norms, injunctive norms, and outright peer pressure. Descriptive norms and injunctive norms are both observed behaviors and are thus more indirect forms of pressure, but differ in one key aspect: descriptive norms describe peers' sexual behaviors, but injunctive norms describe peers' attitudes toward those behaviors (e.g. approval or disapproval). The last norm defined by the study is called "peer pressure" by the authors, and is used to describe direct encouragement or pressure by a person's peers to engage in sexual behavior.
The review found that indirect norms (descriptive and injunctive) had a stronger effect on a person's decision to engage in sexual behavior than direct peer pressure. Between the two indirect norms, descriptive norms had a stronger effect: people were likely to try what they thought their peers were engaging in rather than what they thought had approval in their peer group.
Additionally, studies have found a link between self-regulation and likeliness to engage in sexual behavior. The more trouble a subject had with self-regulation and self-control growing up, the more they were likely to fall prey to peer pressure that would lead them to engage in risky sexual acts. Based on these findings, it may be a good idea to prevent these through either a decision-making program or by targeting adolescents' ability to self-regulate against possible risks.
From a purely neurological perspective, the medial prefrontal cortex (mPFC) and the striatum play an important role in figuring out the value of specific actions. The mPFC is active when determining "socially tagged" objects, which are objects that peers have expressed an opinion about; the striatum is significant for determining the value of these "socially tagged" objects and rewards in general. An experiment performed by Mason et al. utilizing fMRI scans analyzed individuals who were assigned to indicate if a chosen symbol appeared consecutively. The researchers did not tell the subjects the real purpose of the experiment, which was to collect data regarding mPFC and striatum stimulation. Before the actual experiment began, the subjects were subject to a phase of "social" influence, where they learned which symbols were preferred by other subjects of completed the experiment (while in actuality these other subjects did not exist). Mason et al. found that determining an object's social value/significance is dependent on combined information from the mPFC and the striatum [along the lines denoted in the beginning of the paragraph]. Without both present and functional, it would be difficult to determine the value of action based upon social circumstances.
A similar experiment was conducted by Stallen, Smidts, and Sanfrey. Twenty-four subjects were manipulated using a minimal group paradigm approach. Unbeknownst to them, they were all selected as part of the "in-group", although there was an established "out-group". Following this socialization, the subjects estimated the number of dots seen on the screen while given information about what an in-group or out-group member chose. Participants were more likely to conform to in-group decisions as compared to out-group ones. The experiment confirmed the importance of the striatum in social influence, suggesting that conformity with the in-group is mediated with a fundamental value signal—rewards. In other wards, the brain associates social inclusion with positive reward. The posterior superior temporal sulcus (pSTS), which is associated with perspective taking, appeared to be active as well, which correlated with patients' self-reports of in-group trustworthiness.
In adolescence, risk-taking appears to increase dramatically. Researchers conducted an experiment with adolescent males who were of driving age and measured their risk-taking depending on whether a passenger (a peer of the same age) was in the car. A driving simulation was created, and certain risky scenarios, such as a decaying yellow light as the car was approaching, were modeled and presented to the subjects. Those who were most likely to take risks in the presence of peers (but took fewer risks when there were no passengers) had greater brain activity in the social-cognitive and social-affective brain systems during solo activity (no passengers.) The social-cognitive aspect refers to the ability to gauge what others are thinking and is primarily controlled by the mPFC, right temporal parietal junction, and the posterior cingulate cortex. The social-affective aspect relates to the reward system for committing actions that are accepted or rejected by other people. One side of the reward system is "social pain", which refers to the emotional pain felt by individual due to group repudiation and is associated with heightened activity in the anterior insula and the subgenual anterior cingulate cortex.
The Holocaust is probably the most well-known of genocides. In the 1940s, Nazi Germany, led by Adolf Hitler, began a systematic purge against the Jewish people living in Europe, killing around six million Jews by the end of World War II. It is clear that some Germans are culpable for the Holocaust; SS officers and soldiers clearly bought into the Jewish genocide and participated as executioners, jailers, and hunters (for hiding Jews). However, a broader statement is harder to make—as seen below, not all Germans wanted to kill the Jews. When bringing the concept of peer pressure into the Holocaust, German culpability is even harder to decide.
The primary issue revolves around collective responsibility and beliefs. As such, there are two positions, most notably held by Christopher Browning and David Goldhagen.
Browning's 1992 book Ordinary Men: Reserve Police Battalion 101Edit
Christopher Browning, most known for his book Ordinary Men, relies on an analysis of the men in Reserve Police Battalion 101. The men of the 101st were not ardent Nazis but ordinary middle-aged men of working-class background from Hamburg. They were drafted but found ineligible for regular military duty. Their test as an Order Police battalion first came in the form of Jozefow, a Jewish ghetto in Poland. The Battalion was ordered to round up the men in the ghetto and kill all women, children, and elderly on sight. During the executions, a few dozen men were granted release of their execution tasks and were reassigned to guard or truck duty. Others tried to stall as long as possible, trying not to be assigned to a firing squad. After the executions were completed, the men drank heavily, shaken by their ordeal.
At the end of his book, Browning supplies his theory on 101's actions: a combination of authoritative and peer pressure was a powerful coercive tool. First, the Nazi leadership wanted to keep the country's soldiers psychologically healthy, so soldiers were not forced to commit these murders. Throughout the German ranks, nothing negative happened to the soldiers and policemen who refused to join in on a firing squad or Jewish search party. They would simply be assigned other or additional duties, and perhaps subject to a little verbal abuse deriding their "cowardice". For the officers, no official sanction was given, but it was well-known that being unable to carry out executions was the sign of a "weak" leader, and the officer would be passed for promotions. Second, Major Trapp, the head of Battalion 101, consistently offered protection from committing these actions, even so far as supporting one man who was blatantly and vocally against these practices. He established "ground" rules in which only volunteers were taking on 'Jewish Hunts" and raids.
Browning relies on Milgram's experiments on authority to expand his point. Admitting that Trapp was not a particularly strong authority figure, Browning instead points to the Nazi leadership and the orders of the "highest order" that were handed down. Furthermore, according to Browning's analysis, one reason so few men separated themselves from their task was peer pressure—individual policemen did not want to "lose face" in front of their comrades. Some argued that it was better to shoot one and quit than to be a coward immediately. Some superior officers treated those who did not want to execute Jews with disdain; on the other hand, those selected for the executions or Jewish hunts were regarded as real "men" and were verbally praised accordingly. For some, refusing their tasks meant that their compatriots would need to carry the burden and the guilt of abandoning their comrades (as well as fear of ostracization) compelled them to kill.
David Goldhagen's book Hitler's Willing ExecutionersEdit
Goldhagen, disagreeing with Browning's conclusion, decided to write his own book; its release was highly controversial. He argues that the Germans were always anti-Semitic, engaging in a form of "eliminationism". Taking photos of the deceased, going on "Jew-Hunts", death marches near the end of the war, and a general focus on hate (rather than ignorance) are points Goldhagen utilizes in his book.
He does not believe that peer pressure or authoritative pressure can explain why ordinary Germans engaged in these actions. He believes that in order for the policemen in Battalion 101 (and those in similar situations) to kill, they must all be fully committed to the action—no half-heartedness. As he notes,
"For that matter, for someone to be pressured into doing something, by peer pressure, everyone else has to want to do it. Peer pressure can, of course, operate on isolated individuals, or small groups, but it depends upon the majority wanting to do it. So the peer pressure argument contradicts itself. If the majority of the people hadn't wanted to kill Jews, then there would have been peer pressure not to do it" (37).
Instead, he places a significant emphasis on the German people's anti-Semitism, to the extent of drawing ire from other historians. Browning notes Goldhagen's "uniform portrayal" of Germans, dehumanizing all of the perpetrators without looking at the whole picture. For example, in the town of Niezdow, the Police Battalion executed over a dozen elderly Poles in retaliation for the murder of a German policeman. It is less clear, then, if the Germans in the Police Battalion are antagonistic only towards Jews. The German-Canadian historian Ruth Bettina Birn has—in collaboration with Volker Rieß— checked Goldhagen's archival sources from Ludwigsburg. Their findings confirm the arbitrary nature of his selection and evaluation of existing records as opposed to a more holistic combination of primary sources. Furthermore, Konrad Kwiet, a Holocaust historian, argues that Goldhagen's narrow focus on German anti-Semitism has blinded him to other considerations. He points to the massacres of non-Jews as an example:
"[Goldhagen does not shine light] on the motives of “Hitler’s willing executioners” in murdering handicapped people within the so-called “Euthanasia Program”, in liquidating 2.7 million Soviet prisoners of war, in exterminating Romas or in killing hundreds of thousands of other people classified as enemies of the “German People and Nation”. The emphasis on German responsibility allows Goldhagen to push aside the willingness of genocidal killers of other nationalities [such as Latvians] who, recruited from the vast army of indigenous collaborators, were often commissioned with the task of carrying out the ‘dirty work’, such as the murder of women and children, and who, in many cases, surpassed their German masters in their cruelty and spontaneous brutality" (27).
The Rwandan genocide occurred in 1994, with ethnic violence between the Hutu and Tutsi ethnicities. The primary belligerents were the Hutu; however, as with most ethnic conflict conflicts, not all Hutu wanted to kill Tutsi. A survivor named Mectilde described the Hutu breakdown as follows: 10% helped, 30% forced, 20% reluctant, and 40% willing. For the willing, a rewards structure was put in place. For the unwilling, a punishment system was in effect. The combination, Professor Bhavnani argues, is a behavioral norm enforced by in-group policing. Instead of the typical peer pressure associated with western high school students, the peer pressure within the Rwandan genocide, where Tutsi and Hutu have inter-married, worked under coercion. Property destruction, rape, incarceration, and death faced the Hutu who were unwillingly to commit to the genocide or protected the Tutsi from violence.
When looking at a sample community of 3426 in the village of Tare during the genocide, McDoom found that neighborhoods and familial structures as important micro-spaces that helped determine if an individual would participate in violence. Proximity increases the likelihood of social interaction and influence. For example, starting at a set point such as the home of a "mobilizing" agent for the Hutu (any individual who planned or led an attack in the village), the proportion of convicts living in a 100m radius of a resident is almost twice as many for convicts (individuals convicted of genocide by the gacaca, a local institution of transitional justice that allows villagers to adjudicate on many of the perpetrators’ crimes by themselves) as for non-convicts. As the radius increases, so does the proportion decrease. This data hints that "social influence" was at play. Looking at neighborhoods, an individual is 4% more likely to join the genocide for every single percentage point increase in the proportion of convicted perpetrators living within a 100m radius of them. Looking at familial structures, for any individual, each percentage point increase in the proportion of genocide participants in the individual's household increased his chances of joining the violence by 21 to 25%.
Of course, the complete situation is a little more nuanced. The extreme control of citizens' daily lives by the government in social affairs facilitated the rapidity of the genocide's spread and broke down the resolve of some who initially wanted to have no part in the genocide. First, prior to the genocide, Rwandans' sense of discipline was introduced and reinforced through weekly umuganda (collective work) sessions, involving praise for the regime and its leaders and a host of collective activities for the community. Respect for authority and the fear of stepping out of line were strong cultural values of pre-genocide Rwanda and so were included in these activities. Second, their value of social conformity only increased in the decades leading up to the genocide in both social and political manners. Peasants were told exactly when and what to farm and could be fined given any lack of compliance. These factors helped to drive the killing's fast pace.
Most importantly, there were already ethnic tensions among the groups for a variety of reasons: conflicts over land allocation (farming versus pasture) and declining prices of Rwanda's main export: coffee. These problems combined with a history of previously existing conflict. With the introduction of the Second Republic under Habyarimana, former Tutsis in power were immediately purged, and racism served as an explanation as keeping the majority Hutu in legitimate government power. As a result, when the war came, the Hutu were already introduced to the concept of racism against their very own peers.
The division in Rwanda was reinforced for hundreds of years. King Kigeli IV, a Tutsi, centralized Rwandan power in the 1800s, just in time for German colonization. The Germans furthered the message of distinct races, allowing Tutsi men to remain the leaders in the society.
As a leadership toolEdit
In software developmentEdit
Agile software development is a relatively new software development methodology involving a focus on people rather than processes, features rather than tasks, continuous rather than formal communication, and continuous rather than one-time customer involvement. In agile development, one important characteristic is the focus on peer development. Used correctly by management, this focus on teamwork can reinforce correct work through positive and negative mechanisms (rewards vs. sanctions.)
Code reviews, where one developer invites one or more of her peers to review the written code before it is put into production, can make sure that developers are not producing incorrect and sloppy code. Because peers look at each other's code and structure, developers are compelled to write quality code to dispel the fear of being judged by their co-workers. Automated testing and continuous integration with the project can highlight deficiencies and provoke an increase in work quality. However, this form of peer pressure should be balanced accordingly. Developers who have low esteem but are performing well can feel inadequate in a transparent environment, while other developers can form large egos.
Scrum meetings are a good example of the positive results of successful agile management. These meetings include all developers and the project manager. During these scrum meetings, developers can talk about what they accomplished the previous day. Group recognition (informal awards,) the positive side of peer pressure, can manifest as a result when a developer fixed a critical bug or released an important feature. On the other hand, for the individuals who did not work hard, their statements during scrum will likely be short. Because all workers know what the others are tasked with and have accomplished, developers, in order to (at the very least) appear to have worked hard, strive to have more to say during these meetings; in most cases, this occurs when the coder has actually completed a good amount of work.
Agile teams are much like a self-managing teams, where internal forces and peer pressure within the team direct the day-to-day activities. In the case of agile, there is a still a formal manager, but he might play a less vocal role in decisions. Agile teams are structured so that the project manager does less work managing (since there is already peer pressure as a control system in place) and more time with the business clients.
In schools, peer pressure is a manifestation of informal accountability pressure. Principals who had a strong rapport with their teachers and engaged in mutually respectful conversations were able to leverage their relationships with teachers through peer pressure—the teacher does not want to disappoint the principal and let her down. Similarly, principals who served as strong "instructional" leaders and introduced new curricula and academic programs were able to create a system of peer pressure at the teaching level, where the teachers placed accountability pressure on themselves.
Peer pressure can be especially effective (more so than door-to-door visits and telephone calls) in getting people to vote. Gerber, Green, and Larimer conducted a large-scale field experiment involving over 180,000 Michigan households in 2006 and four treatments: one was a reminder to vote, one was a reminder to vote and a note informing them that they were being studied, one that listed the voting records for all potential household individuals, and finally one that listed the voting records for the household individuals and their neighbors. The final treatment emphasized peer pressure within a neighborhood; neighbors could view each other's voting habits with the lists, and so the social norm of "voting is best for the community" is combined with the fear that individuals' peers would judge their lack of voting. Compared to a baseline rate of 29.7% (only the voting reminder), the treatment that utilized peer pressure increased the percentage of household voters by 8.1% (to 37.8%), which exceeds the value of in-person canvassing and personalized phone calls.
For charitable donationsEdit
An experiment conducted by Diane Reyniers and Richa Bhalla measured the amount donated by a group of London School of Economics students. The group was split into individual donators and pair donators. The donation amounts were revealed within each pair; then, the pair was given time to discuss their amounts and then revise them as necessary. In general, pair subjects donated an average of 3.64 pounds (Sterling) while individuals donated an average of 2.55 pounds. Furthermore, in pairs where one subject donated significantly more than the other, the latter would on average increase the donation amount by 0.55 pounds. This suggests that peer pressure "shames" individuals for making smaller donations; interestingly enough, when controlling for donation amount, paired subjects were significantly less happy with their donation amount than individual subjects—suggesting that paired subjects felt coerced to donate more than they would have otherwise. This leads to a dilemma: charities will do better by approaching groups of people (such as friends); however, this could result in increased donor discomfort, which would impact their future donations.
- Corriveau, Kathleen H.; Harris, Paul L. (2010-03-01). "Preschoolers (sometimes) defer to the majority in making simple perceptual judgments.". Developmental Psychology. 46 (2): 437–445. ISSN 1939-0599. PMID 20210502. doi:10.1037/a0017553.
- Haun, Daniel B. M.; Tomasello, Michael (2011-11-01). "Conformity to Peer Pressure in Preschool Children". Child Development. 82 (6): 1759–1767. ISSN 1467-8624. doi:10.1111/j.1467-8624.2011.01666.x. Cite error: Invalid
<ref>tag; name ":22" defined multiple times with different content (see the help page).
- Carden Smith, L. K.; Fowler, S. A. (1984-01-01). "Positive peer pressure: the effects of peer monitoring on children's disruptive behavior". Journal of Applied Behavior Analysis. 17 (2): 213–227. ISSN 0021-8855. PMC . PMID 6735953. doi:10.1901/jaba.1984.17-213.
- B. B. Brown, "Adolescents' relationships with peers," In: R. M. Lerner & L. Steinburg (Eds.), Handbook of Adolescent Psychology, 2nd ed, New York: Wiley, 2004, p 363-394.
- Steinberg, Laurence; Monahan, Kathryn C. (2007). "Age differences in resistance to peer influence". Developmental Psychology. 43 (6): 1531–1543. PMC . PMID 18020830. doi:10.1037/0012-16184.108.40.2061.
- Kevin Durkin, "Peer Pressure", In: Anthony S. R. Manstead and Miles Hewstone (Eds.), The Blackwell Encyclopedia of Social Psychology, 1996.
- Spear, Hila J.; Kulbok, Pamela A (2001). "Adolescent Health Behaviors and Related Factors: A Review". Public Health Nursing. 18 (2): 82–93. PMID 11285102. doi:10.1046/j.1525-1446.2001.00082.x.
- Stephanie Hanes, "Teens and volunteering: Altruism or just peer pressure?" The Christian Science Monitor, October 25, 2012.
- Kellie B. Gormly, "Peer Pressure -- for students and adults -- can be positive," Pittsburgh Tribune-Review, March 18, 2013.
- Brown, B. Bradford; Eicher, Sue Ann; Petrie, Sandra (1986). "The importance of peer group ("crowd") affiliation in adolescence". Journal of Adolescence. 9 (1): 73–96. doi:10.1016/S0140-1971(86)80029-X.
- Allen, Joseph P.; Porter, Maryfrances R.; McFarland, F. Christy; Marsh, Penny; McElhaney, Kathleen Boykin (2005). "The Two Faces of Adolescents' Success With Peers: Adolescent Popularity, Social Adaptation, and Deviant Behavior". Child Development. 76 (3): 747–760. PMC . PMID 15892790. doi:10.1111/j.1467-8624.2005.00875.x.
- Brown, B. Bradford. "The extent and effects of peer pressure among high school students: A retrospective analysis". Journal of Youth and Adolescence. 11 (2): 121–133. ISSN 0047-2891. doi:10.1007/BF01834708.
- Clasen, Donna Rae; Brown, B. Bradford. "The multidimensionality of peer pressure in adolescence". Journal of Youth and Adolescence. 14 (6): 451–468. ISSN 0047-2891. doi:10.1007/BF02139520.
- Bahr, Stephen J.; Hoffmann, John P.; Yang, Xiaoyan (15 October 2005). "Parental and Peer Influences on the Risk of Adolescent Drug Use". The Journal of Primary Prevention. 26 (6): 529–551. doi:10.1007/s10935-005-0014-8.
- Urberg, Kathryn A.; Shiang-Jeou, Shyu; Liang, Jersey (1990). "Peer influence in adolescent cigarette smoking". Addictive Behaviors. 15 (3): 247–255. PMID 2378284. doi:10.1016/0306-4603(90)90067-8.
- Farrell, Albert D.; White, Kamila S. (April 1998). "Peer influences and drug use among urban adolescents: Family structure and parent-adolescent relationship as protective factors.". Journal of Consulting and Clinical Psychology. 66 (2): 248–258. doi:10.1037/0022-006X.66.2.248.
- Dielman, T. E.; Butchart, A. T.; Shope, J. T. (1993). "Structural Equation Model Tests of Patterns of Family Interaction, Peer Alcohol Use, and Intrapersonal Predictors of Adolescent Alcohol Use and Misuse". Journal of Drug Education. 23 (3): 273–316. doi:10.2190/8YXM-K9GB-B8FD-82NQ.
- Steinberg, Laurence; Fletcher, Anne; Darling, Nancy (1 June 1994). "Parental Monitoring and Peer Influences on Adolescent Substance Use". Pediatrics. 93: 1060. doi:10.1017/CBO9780511527906.016.
- Caldwell, Linda; Darling, Nancy (1999). "Leisure Context, Parental Control, and Resistance to Peer Pressure as Predictors of Adolescent Partying and Substance Use: An Ecological Perspective". Journal of Leisure Research. 31 (1).
- Maxwell, Kimberly A. (August 2002). "Friends: The Role of Peer Influence Across Adolescent Risk Behaviors". Journal of Youth and Adolescence. 31 (4): 267–277. doi:10.1023/A:1015493316865.
- Allen, Joseph P.; Porter, Maryfrances R.; McFarland, F. Christy (2006). "Leaders and followers in adolescent close friendships: Susceptibility to peer influence as a predictor of risky behavior, friendship instability, and depression". Development and Psychopathology. 18 (01). PMC . PMID 16478557. doi:10.1017/S0954579406060093.
- Kendler, Kenneth S.; Prescott, Carol A.; Myers, John; Neale, Michael C. (September 2003). "The Structure of Genetic and Environmental Risk Factors for Common Psychiatric and Substance Use Disorders in Men and Women". Archives of General Psychiatry. 60 (9): 929–937. doi:10.1001/archpsyc.60.9.929.
- Harden, K. Paige; Hill, Jennifer E.; Turkheimer, Eric; Emery, Robert E. (27 March 2008). "Gene-Environment Correlation and Interaction in Peer Effects on Adolescent Alcohol and Tobacco Use". Behavior Genetics. 38 (4): 339–347. doi:10.1007/s10519-008-9202-7.
- Johnson, Eric O.; Chen, Li-Shiun; Breslau, Naomi; Hatsukami, Dorothy; Robbins, Tania; Saccone, Nancy L.; Grucza, Richard A.; Bierut, Laura J. (November 2010). "Peer smoking and the nicotinic receptor genes: an examination of genetic and environmental risks for nicotine dependence". Addiction. 105 (11): 2014–2022. PMC . PMID 20840187. doi:10.1111/j.1360-0443.2010.03074.x.
- Sumter, Sindy R.; Bokhorst, Caroline L.; Steinberg, Laurence; Westenberg, P. Michiel (August 2009). "The developmental pattern of resistance to peer influence in adolescence: Will the teenager ever be able to resist?". Journal of Adolescence. 32 (4): 1009–1021. doi:10.1016/j.adolescence.2008.08.010.
- Merikangas, Kathleen Ries; He, Jian-ping; Burstein, Marcy; Swanson, Sonja A.; Avenevoli, Shelli; Cui, Lihong; Benjet, Corina; Georgiades, Katholiki; Swendsen, Joel (October 2010). "Lifetime Prevalence of Mental Disorders in U.S. Adolescents: Results from the National Comorbidity Survey Replication–Adolescent Supplement (NCS-A)". Journal of the American Academy of Child & Adolescent Psychiatry. 49 (10): 980–989. doi:10.1016/j.jaac.2010.05.017.
- Marshal, Michael P.; Chassin, Laurie (March 2000). "Peer Influence on Adolescent Alcohol Use: The Moderating Role of Parental Support and Discipline". Applied Developmental Science. 4 (2): 80–88. doi:10.1207/S1532480XADS0402_3.
- Tobler, Nancy (1986). "Meta-analysis of 143 adolescent drug prevention programs: Quantitative outcome results of program participants compared to a control or comparison group". Journal of Drug Issues. 16 (4): 537–567.
- Hansen, William B.; Graham, John W. (May 1991). "Preventing alcohol, marijuana, and cigarette use among adolescents: Peer pressure resistance training versus establishing conservative norms". Preventive Medicine. 20 (3): 414–430. doi:10.1016/0091-7435(91)90039-7.
- Foxcroft, David; Ireland, Diana; Lowe, Geoff; Breen, Rosie. "Primary prevention for alcohol misuse in young people". Protocols. Cochrane Drugs and Alcohol Group. doi:10.1002/14651858.CD003024.
- Foxcroft, David R; Tsertsvadze, Alexander (March 2012). "Cochrane Review: Universal school-based prevention programs for alcohol misuse in young people". Evidence-Based Child Health: A Cochrane Review Journal. 7 (2): 450–575. doi:10.1002/ebch.1829.
- Shope, Jean T.; Copeland, Laurel A.; Maharg, Ruth; Dielman, T.E. (August 1996). "Effectiveness of a High School Alcohol Misuse Prevention Program". Alcoholism: Clinical and Experimental Research. 20 (5): 791–798. doi:10.1111/j.1530-0277.1996.tb05253.x.
- Onrust, Simone A.; Otten, Roy; Lammers, Jeroen; Smit, Filip (2016-03-01). "School-based programmes to reduce and prevent substance use in different age groups: What works for whom? Systematic review and meta-regression analysis". Clinical Psychology Review. 44: 45–59. doi:10.1016/j.cpr.2015.11.002.
- Khemka, Ishita; Hickson, Linda; Mallory, Sarah B. (2016-03-18). "Evaluation of a Decision-Making Curriculum for Teaching Adolescents with Disabilities to Resist Negative Peer Pressure". Journal of Autism and Developmental Disorders. 46 (7): 2372–2384. ISSN 0162-3257. doi:10.1007/s10803-016-2770-0.
- "Evaluation of a decision-making curriculum for teaching adolescents with di...: EBSCOhost". web.a.ebscohost.com. Retrieved 2016-11-01.
- "Influence of Teens' Perceptions of Parental Disapproval and Peer Behaviour on Their Initiation of Sexual Intercourse". The Canadian Journal of Human Sexuality. 14.
- SELIKOW, AHMED, FLISHER, MATHEWS, MUKOMA. "I am not ‘‘umqwayito’’: A qualitative study of peer pressure and sexual risk behaviour among young adolescents in Cape Town, South Africa". Scandinavian Journal of Public Health, 2009. 37(Suppl 2): 107–112.
- Bongardt, Daphne van de; Reitz, Ellen; Sandfort, Theo; Deković, Maja (2015-08-01). "A Meta-Analysis of the Relations Between Three Types of Peer Norms and Adolescent Sexual Behavior". Personality and Social Psychology Review. 19 (3): 203–234. ISSN 1088-8683. PMID 25217363. doi:10.1177/1088868314544223.
- Crockett. "Linking Self-Regulation and Risk Proneness to Risky Sexual Behavior: Pathways through Peer Pressure and Early Substance Use". Faculty Publications, Department of Psychology.
- Mason, Malia; Dyer, Rebecca; Norton, Michael. "Neural Mechanisms of Social Influence". Organizational Behavior and Human Decision Processes. 110: 152–159. doi:10.1016/j.obhdp.2009.04.001.
- Stallen, Mirre; Smidts, Ale; Sanfey, Alan. "Peer influence: neural mechanisms underlying in-group conformity". Frontiers in Human Neuroscience. 7 (50).
- Eisenberger, Naomi I.; Lieberman, Matthew D.; Williams, Kipling D. (2003-10-10). "Does Rejection Hurt? An fMRI Study of Social Exclusion". Science. 302 (5643): 290–292. ISSN 0036-8075. PMID 14551436. doi:10.1126/science.1089134.
- Falk, Emily B.; Cascio, Christopher N.; O'Donnell, Matthew Brook; Carp, Joshua; Tinney, Francis J.; Bingham, C. Raymond; Shope, Jean T.; Ouimet, Marie Claude; Pradhan, Anuj K. "Neural Responses to Exclusion Predict Susceptibility to Social Influence". Journal of Adolescent Health. 54 (5): S22–S31. doi:10.1016/j.jadohealth.2013.12.035.
- Klee, Ernst; Dressen, Willi; Reiss, Volker (1996). The Good Old Days: The Holocaust as Seen by Its Perpetrators and Bystanders. New York: The Free Press. ISBN 978-1568521336.
- Browning, Christopher (1998). Ordinary Men: Reserve Police Battalion 101 and the Final Solution in Poland. London: Penguin. ISBN 978-0060995065.
- Goldhagen, Daniel Jonah; Wohlgelernter, Maurice. "Hitler’s willing executioners". Society. 34 (2): 32–37. ISSN 0147-2011. doi:10.1007/BF02823096.
- Browning, Christopher (1996). "Daniel Goldhagen's Willing Executioners". History and Memory. 8: 88–108.
- KWIET, KONRAD (1997). "Goldhagen, the Germans, and the Holocaust". Journal of Jewish Affairs. 133: 7–39.
- Bhavnani, Ravi (2006-11-01). "Ethnic Norms and Interethnic Violence: Accounting for Mass Participation in the Rwandan Genocide". Journal of Peace Research. 43 (6): 651–669. ISSN 0022-3433. doi:10.1177/0022343306069290.
- McDoom, Omar Shahabudin (2013-07-01). "Who killed in Rwanda’s genocide? Micro-space, social influence and individual participation in intergroup violence". Journal of Peace Research. 50 (4): 453–467. ISSN 0022-3433. doi:10.1177/0022343313478958.
- Hintjens, Helen (1999). "Explaining the 1994 Genocide in Rwanda". The Journal of Modern African Studies. 37: 241–286. doi:10.1017/s0022278x99003018.
- Conboy, Kieran; Coyle, Sharon; Pikkarainen, Minna; Wang, XiaoFeng. "People over process: key people challenges in agile development". IEEE. 28 (4): 48–57. doi:10.1109/ms.2010.132.
- Persson, John; Mathiassen, Lars; Aaen, Ivan. "Agile Distributed Development". Information Systems Journal. 22 (6): 411–433. doi:10.1111/j.1365-2575.2011.00390.x.
- Jacobson, Stephen; Johnson, Lauri; Ylimaki, Rose; Giles, Corrie. "Successful leadership in challenging US schools: enabling principles, enabling schools". Journal of Educational Administration. 43 (6): 607–618. doi:10.1108/09578230510625700.
- Gerber, Alan S.; Green, Donald P.; Larimer, Christopher W. (2008-02-01). "Social Pressure and Voter Turnout: Evidence from a Large-Scale Field Experiment". American Political Science Review. 102 (1): 33–48. ISSN 1537-5943. doi:10.1017/S000305540808009X.
- Reyniers, Diane; Bhalla, Richa (2013). "Reluctant altruism and peer pressure in charitable giving". Judgment and Decision Making. 8 (1): 7–15.
- Browning, Christopher R. (1998). Ordinary Men: Reserve Police Battalion 101 and the Final Solution in Poland (reprint ed.). Harper Perrenial. ISBN 0-060-99506-8.
- Goldhagen, Daniel (1996). Hitler's Willing Executioners: Ordinary Germans and The Holocaust. New York: Alfred A. Knopf. ISBN 978-0-679-44695-8.