In This Article Expand or collapse the "in this article" section Effects of the 9/11 Terrorist Attacks on American Public Opinion and Behavior

  • Introduction
  • Risk Perceptions, Emotional Reactions, and Disorders Following 9/11
  • Attitudes toward Outgroups and Policies that Affect These Groups
  • Trust and Patriotism
  • Ideology
  • Evaluations of Leaders and Voting Behavior
  • Terrorism and Media Coverage

Political Science Effects of the 9/11 Terrorist Attacks on American Public Opinion and Behavior
Carlin Crisanti, Jennifer Merolla
  • LAST REVIEWED: 27 February 2019
  • LAST MODIFIED: 27 February 2019
  • DOI: 10.1093/obo/9780199756223-0270


The September 11th attacks were the deadliest international terrorist attacks to have occurred on US soil, and have had profound effects on American public opinion. Ever since that day, researchers from various fields have been investigating the ways in which these highly traumatic events have affected the American public. As we are interested in chronicling the multitude of public responses to these attacks, we draw not only from the field of political science, but also from other fields such as sociology, economics, psychology, and medicine. Although this is a vast literature, we have identified seven broad categories that capture how the American people reacted in the aftermath of the attacks, and given reminders of the attacks. The seven fields are as follows: (1) risk perceptions, emotions, and disorders; (2) attitudes toward outgroups and the policies which affect them; (3) trust and patriotism; (4) ideology; (5) policy preferences; (6) evaluations of leaders and voting behavior: and (7) media coverage. We also note that all of the studies in this review deal specifically with 9/11 or reminders of 9/11 in the US context. There is a much richer literature that explores the effects of terrorist attacks more generally both within and outside of the United States.

Risk Perceptions, Emotional Reactions, and Disorders Following 9/11

Perhaps one of the most studied outcomes of the September 11th terrorist attacks are the widespread psychological effects which were witnessed among the American public. Some of the earliest research published in Silver, et al. 2002 pertained to the various stress and depressive disorders witnessed in the population after the attacks. Later investigations such as Bonanno, et al. 2007 and Chu, et al. 2006 delve in to which groups of people were most resilient or best able to cope with the trauma. The more recent work in this area, such as North, et al. 2015, has been looking at the long-term effects on highly exposed individuals from New York City. Another area studied is risk perceptions, or how threatened the public felt as a result of the attacks. The research in Fischhoff, et al. 2003; Huddy, et al. 2005; and Lerner, et al. 2003 seems to converge on the idea that the attacks elevated personal risk perceptions linked to terrorism, although there is not a definitive consensus as to how quickly these effects diminished. Another strand of scholarship examines emotional reactions to the attacks felt by a broad cross-section of the public. These works primarily focus on negative affect experienced by the American people and how these felt emotions are related yet often quite distinct. The most common negative emotions studied are anger, fear, anxiety, and sadness and these are often linked with other political outcomes as seen in the works of Huddy, et al. 2007; Huddy, et al. 2005; and Merolla and Zechmeister 2009. Emotional reactions to the terrorist attacks have even been studied at the physiological level in Ganzel, et al. 2007, which imaged the amygdala region of the brain (which is responsible for how emotions are experienced).

  • Bonanno, G. A., S. Galea, A. Bucciarelli, and D. Vlahov. “What Predicts Psychological Resilience after Disaster? The Role of Demographics, Resources, and Life Stress.” Journal of Consulting and Clinical Psychology 75 (2007): 671–682.

    DOI: 10.1037/0022-006X.75.5.671

    Using data collected from a survey in New York City six months after the attacks, this study found older individuals, males, and those with lower levels of education were more psychologically resilient than their counterparts. In addition to age, gender, and education level, psychological resilience was also predicted by other factors such as: race/ethnicity, past trauma exposure, income change, social support, frequency of chronic illness, and other life stressors.

  • Chu, T. Q., M. D. Seery, W. A. Ence, A. Holman, and R. Silver. “Ethnicity and Gender in the Face of a Terrorist Attack: A National Longitudinal Study of Immediate Responses and Outcomes Two Years after September 11.” Basic and Applied Social Psychology 28 (2006): 291–301.

    DOI: 10.1207/s15324834basp2804_2

    This article looks specifically at immediate and predicted long-term (two years after) ethnic and sex differences in responses to the 9/11 attacks. Blacks and women were found to respond with more emotion and were less likely to support violent retaliation than their white and male counterparts. Higher levels of distress and PTS (post-traumatic stress) symptoms over time were associated with sad/sympathetic responses and endorsing violent retaliation.

  • Fischhoff, B., R. M. Gonzalez, D. A. Small, and J. S. Lerner. “Judged Terror Risk and Proximity to the World Trade Center.” Journal of Risk and Uncertainty 26 (2003): 137–151.

    DOI: 10.1023/A:1024163023174

    Using a survey experiment two months after the attacks, the authors examined participant judgments of terror related events and routine risk for the next twelve months. Subjects felt greater personal risk from terror events (but not routine risks) post-9/11 if they lived within one hundred miles of the World Trade Center, however this sensitivity was not found across all demographic groups. Emotions did not seem to be related to proximity.

  • Ganzel, B., B. J. Casey, G. Glover, H. U. Voss, and E. Temple. “The Aftermath of 9/11: Effect of Intensity and Recency of Trauma on Outcome.” Emotion 7 (2007): 227–238.

    DOI: 10.1037/1528-3542.7.2.227

    Using fMRIs, this study looks specifically at whether proximity to the attacks of 9/11 altered amygdala function (the area of the brain responsible for how emotions are experienced) up to three years after exposure. Bilateral amygdala activity in response to viewing frightened faces was higher (compared to a calm face) in subjects who were proximally closer to Ground Zero during the attacks.

  • Huddy, L., S. Feldman, and E. Cassese. “On the Distinct Political Effects of Anxiety and Anger.” In The Affect Effect: Dynamics of Emotion in Political Thinking and Behavior. Edited by W. R. Neuman, G. E. Marcus, A. Crigler, and M. MacKuen, 202–230. Chicago: University of Chicago Press, 2007.

    DOI: 10.7208/chicago/9780226574431.003.0009

    This chapter examines how emotional responses shaped political reactions to the Iraq war in the six months immediately following 9/11 using data from the Threat and National Security Survey (TNSS). Relevant to this heading, the study showed that experiences of anxiety (measured as nervous, scared, and afraid) and anger (angry, hostile, and disgusted) in reaction to 9/11 and terrorism more generally were related, but empirically distinct.

  • Huddy, L., S. Feldman, C. Taber, and G. Lahav. “Threat, Anxiety, and Support of Anti-terrorism Policies.” American Journal of Political Science 49 (2005): 593–608.

    DOI: 10.1111/j.1540-5907.2005.00144.x

    Using data from a survey administered between October 2001 and March 2002, the authors examine predictors of the perceived threat of terrorism and the experience of anxiety. Some key findings are that people living near the attacks had significantly higher levels of anxiety and perceptions of threat with close physical proximity having the greatest impact on anxiety. Anxiety was also pronounced among women, Democrats, and younger individuals.

  • Lerner, J. S., R. M. Gonzalez, D. A. Small, and B. Fischhoff. “Effects of Fear and Anger on Perceived Risks of Terrorism: A National Field Experiment.” Psychological Science 14 (2003): 144–150.

    DOI: 10.1111/1467-9280.01433

    This article examines how emotions affect citizen response to risk. Administering a two-wave survey experiment shortly after 9/11, the authors assessed whether or not emotions about future attacks altered beliefs and attitudes of the general public. Anger was found to result in more optimistic beliefs whereas fear triggered greater pessimism. Across all risks (terror and non-terror), males expressed less pessimistic risk estimates.

  • Merolla, J. L., and E. J. Zechmeister. Democracy at Risk: How Terrorist Threats Affect the Public. Chicago: University of Chicago Press, 2009.

    DOI: 10.7208/chicago/9780226520568.001.0001

    This book examines how the public copes with the threat of international terrorism drawing from data in the United States and Mexico. Across six experiments, the authors found that exposure to news about terrorism, including reminders about 9/11, increased negative emotions and diminished positive emotions. This effect held across countries and whether the news was delivered as an audiovisual segment or as print media without visuals.

  • North, C. S., D. E. Pollio, B. A. Hong, A. Pandya, R. Smith, and B. Pfefferbaum. “The Post-disaster Prevalence of Major Depression Relative to PTSD in Survivors of the 9/11 Attacks on the World Trade Center Selected from Affected Workplaces.” Comprehensive Psychiatry 60 (2015): 119–125.

    DOI: 10.1016/j.comppsych.2015.02.009

    Three years after the attacks, this study conducted structured interviews with people from eight companies, which were substantially affected through employee exposure or as part of 9/11 rescue and recovery operations. Major depressive disorder (MDD) was significantly more prevalent in women than in men (both pre-disaster and post-disaster). MDD episodes were not associated with race, age, or college education, and married individuals demonstrated more resilience.

  • Silver, R. C., A. E. Holman, D. N. McIntosh, M. Poulin, and V. Gil-Rivas. “Nationwide Longitudinal Study of Psychological Responses to September 11.” JAMA 288 (2002): 1235–1244.

    DOI: 10.1001/jama.288.10.1235

    This study looks at longitudinal adjustment to trauma using data from a three-wave survey approximately six months after the attacks. Increased levels of post-traumatic stress symptoms were found to be associated with a variety of demographic and health variables. Psychological effects of such a large national trauma were not limited to those who experienced it directly, but extended to those who watched it on live TV.

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