People tend to base evaluations of outcomes or consequences on informational attributes of high symbolic significance, while ignoring other crucial information. For example, they strongly rely on symbolic meaning that relates to the naturalness of the cause of a hazard (human vs. nature-caused), and this may result in biased judgments (Siegrist and Sütterlin 2014). The misleading effect of symbolically significant information has been shown in risk assessments of solar and nuclear power-generation technologies. The current study provides evidence for this bias, for an energy source that has become a critical focus in the energy debates in certain countries—namely, hydraulic fracturing or "fracking"—and investigates the underlying process further.
In an online experiment, participants were provided with a text describing how several hundred animals had died due to toxic chemicals that had been released into the soil and entered the water of a nature reserve. The participants were told either that 1) the chemicals had originated from a burst pipe of a fracking installation ("man-made” chemicals, human cause), 2) the chemicals were naturally occurring but were released because of vibrations caused by a nearby fracking installation (natural chemicals, human cause), or 3) the chemicals were naturally occurring and were released because of an earthquake (natural chemicals, natural cause). Our analyses revealed that participants perceived the identical outcome (i.e., the death of several hundred animals) as being more severe when the hazard was human-caused (i.e., fracking) than when it was caused by nature (i.e., earthquake). Furthermore, the participants perceived animal suffering to be lower when they died because of naturally occurring chemicals released by an earthquake, compared to chemicals released from the burst pipe of a fracking installation.
The present findings on risk assessments of fracking suggest that people base their evaluations of outcomes primarily on the nature of the cause and its symbolic meaning, and this results in biased judgments. This bias is driven by the cause of the hazard, rather than the naturalness of the "direct cause" of the negative effect (i.e., chemicals). This study’s findings provide further evidence of people's propensity to rely on the symbolic meaning of the cause of a hazard, rather than on concrete information about outcomes; it also shows how this propensity tends to bias evaluations of energy sources and environmental hazards in general.