Terrorism

   Researchers have identified two types of  risks: unknown risk and dread risk. Dread risks are associated with catastrophic and fatal outcomes and lack of control. An example to this could be a threat of a nuclear war.

   Gigerenzer (2004) proposed, that after the 11th of September (2001) terrorist attacks in the US, people perceived flying as a dread risk. This is because airplanes were used as a tool for terrorism in those attacks. He further proposed, that many people decided to drive instead of flying soon after the attacks, to reduce the risk of dying in a similar way. If this were the case then one could expect an increase in traffic fatalities. 

   To support his hypothesis, Gigerenzer (2004) compared domestic air travel, driving miles and fatal traffic accidents in the months before and after September 11. He found that there were 317 extra fatal traffic fatalities and 353 "surplus" traffic fatalities in the three months after September 11. He also concluded a second analysis using a longer time frame to see the long-term impact of the attacks and found that 1595 more traffic fatalities occurred between October 2001 and March 2003 than expected if there wouldn't have been any terrorist attacks.

   Su and colleauges (2008) found limitations in Gigerenzer's study. They proposed that firstly, his analysis was descriptive and the basic assumptions were not tested for statistical significance, and secondly, his hypothesis is grounded on changes in the amount of people drove after the attacks. It is true, that less flying and more driving could lead to more fatal traffic fatalities, but driving associated risks are not stable over time and place. For example non-weather-related factors can affect the quality of driving and consequently, the number of fatal traffic accidents (Redelmeier& Stewart, 2003; Selzer & Vinokur, 1975).

   Su and colleauges (2008) proposed, that increase in traffic fatalities took place in the areas closer to the attacks and was more related to how people drove rather than how much.

   Evidence has shown, that people living closer to the sites of the terrorist attacks reported higher levels of stress in the few months directly after the attacks. Relationship between self-reported symptoms of posttraumatic stress disorder and geographic proximity to the attacks has also been found. (Schlenger et al., 2002)

   Stress has been related to impaired driving (Selzer & Vinokur, 1975). It is possible, that increase in traffic fatalities took place closer to the terrorist sites, because people's stress levels in these regions were higher and their quality of driving was therefore lower. It is further possible, that elevated stress levels led to driving under influence (alcohol, drugs). This has been termed a regional impaired driving effect. Su and colleauges (2008) proposed that any increase in traffic fatalities was more pronounced in the Northeast and around Washington, DC, than in other parts of the country.

   Su and colleauges (2008) re-examined Gigerenzer's dread hypothesis by applyng formal statistical tests to the same data in the same time frames where possible and also testes the regional impaired driving effect. They tested whether:

• U.S domestic flying miles decreased in the three months following the attacks, compared to the same months in the previous years
• total US driving miles increased in the three months following the attacks, compared to the same months in the previous years and whether this increase was greater than historical trends would predict
• the percentage increase in fatal traffic accidents and traffic fatalities was greater than expected in the three months after the attacks

   They did this by using data from the appropriate federal agencies' Web sites and found, that:

• indeed, the US domestic air travel decreased significantly in the three months following the September 11 attacks in 2001, compared to the same months in the previous years
• there was no notable increase in driving miles in the three months after the attacks compared to the same months in the previous years and any observed increase by Gigerenzer was normative according to the historical trends
• there was also no notable increase in traffic fatalities across the US in the three months following the attacks, compared to the same months in the previous years.The number of fatal traffic accidents in the US increased, but only marginally. There was no evidence of an overall increase in traffic fatalities.
• however, there was a significant increase in traffic fatalities in the Northeast region, with the Twin Towers (although, there was no significant increase in driving miles in the same region- meaning the increase in traffic fatalities in the region was not due to people driving more). The same effect was not observed in Northern South Atlantic region, with Pentagon. Perhaps the effects of the attack on Pentagon was experienced less widely than the attack on New York Twin Towers.
• there was a significant increase in the Northeast region in alcohol and drug-related citations issued in connection with the accidents. This supports the regional impaired-driving effect. It is important to note, that we cannot assume causal relationship, since numerous other factors could also be possible. For example, after the terrorist attacks in New York, there were likely to be many road blocks and traffic diversions in place, which means people would have been driving in unfamiliar settings. This is one factor which could have possibly have impact on the way people drove.

 

  References:

 

 Gigerenzer, G. (2004). Dread Risk, September 11, and fatal traffic accidents. Psychological Science, 15, 286-187.

 

 Redelmeier, D.A., & Stewart, C.L. (2003). Driving fatalities on Super Bowl Sunday. New England Journal of Medicine, 348, 368-369.

    

 Schlenger, W.E., Caddell, J.M., Ebert, L., Jordan, B.K., Rourke, K.M., Wilson, D., et al. (2002). Psychological reactions to terrorist attacks: Findings from the National Study of Americans'          Reactions to September 11. Journal of the American Medical Association, 288, 581-588.

 

 Selzer, M.L., & Vinokur, A. (1975). Role of life events in accident causation. Mental Health & Society, 2, 36-54.

 

 Su, J.C., Tran, A.G.T.T., Wirtz, J.G., Langteau, R.A., & Rothman, A.J. (2008). Driving Under the Influence (of Stress). Evidence of a Regional Increase in Impaired Driving and Traffic Fatalities After the September 11 Terrorist Arracks.