A new study suggests that exposure to air pollution, or even imagined exposure to air pollution, may be associated with crime and unethical behaviors such as cheating. The findings, published in the journal Psychological Science, suggest that this link may be due, at least in part, to higher levels of anxiety.
“This research reveals that air pollution may have potential ethical costs that go beyond its well-known toll on health and the environment,” says behavioral scientist Jackson G. Lu of Columbia Business School, the first author of the research. “This is important because air pollution is a serious global issue that affects billions of people — even in the United States, about 142 million people still reside in counties with dangerously polluted air.”
Prior research has suggested that exposure to air pollution increases anxiety, which in turn has been linked to a range of unethical behaviors. The researchers hypothesize that pollution may ultimately increase criminal activity and unethical behavior by increasing anxiety.
First the researchers looked at air pollution and crime data for 9,360 U.S. cities taken over a nine year period. The air pollution data, maintained by the Environmental Protection Agency (EPA), included information about six major pollutants, including particulate matter, carbon monoxide, nitrogen dioxide, and sulfur dioxide.
The crime data, maintained by the US Federal Bureau of Investigation, included information about crimes in seven major categories, such as murder, aggravated assault, and robbery.
The findings show that cities with higher levels of air pollution tend to have higher levels of crime. This association held true even after the researchers accounted for other potential factors, including total population, number of law enforcement employees, median age, gender distribution, race distribution, poverty rate, unemployment rate, unobserved heterogeneity among cities (e.g., city area, legal system), and unobserved time-varying effects (e.g., macroeconomic conditions).
To see if there was a direct, causal link between the experience of air pollution and unethical behavior, the team conducted several more experiments. Since they could not randomly assign participants to physically experience different levels of air pollution, the researchers manipulated whether participants imagined experiencing air pollution.
For example, 256 participants looked at a photo featuring either a polluted scene or a clean scene. They imagined living in that location and reflected on how they would feel as they walked around and breathed the air.
On a supposedly unrelated task, the participants looked at a set of cue words (e.g., sore, shoulder, sweat) and had to identify another word that was linked with each of the cue words (e.g., cold); each correct answer earned them $0.50.
Due to a fake computer glitch, the correct answer appeared if the participants hovered their mouse over the answer box, which the researchers asked them not to do. Unknown to the participants, the researchers recorded how many times the participants peeked at the answer.
The findings show that participants who thought about living in a polluted area cheated more often than did those who thought about living in a clean area.
In another experiment, participants viewed photos of either polluted or clean scenes taken in the exact same locations in Beijing. They were then asked to write about what it would be like to live there. Independent coders rated the essays according to how much anxiety the participants expressed.
Then the researchers counted how often participants cheated in reporting the outcome of a die roll or how often they were willing to use unethical negotiation strategies.
Similar to the previous findings, participants who wrote about living in a polluted location were more likely to engage in unethical behavior compared to those who wrote about living in a clean location; they also expressed more anxiety in their writing. As the researchers hypothesized, anxiety levels appeared to mediate the link between imagining exposure to air pollution and unethical behavior.
Overall, the archival and experimental findings suggest that exposure to air pollution, whether physical or mental, is linked with unethical behavior through increased levels of anxiety.
The researchers note that there may be other mechanisms besides anxiety that link air pollution and unethical behavior. They also acknowledge that imagining being in a polluted area is not the same as experiencing actual air pollution. They highlight these limitations as avenues for further research.