Explaining Dread Risks: An Evolutionary Perspective
The swine flu pandemic has been accompanied by wide-spread feelings of dread. These feelings may originate from a concern that one’s whole community will be killed within a short time period. We hypothesized that people will dread risks that can kill the number of people equivalent to the approximate size of groups in which humans lived throughout their evolutionary history. Dunbar (1993) suggested that the typical size of these groups was between 100 and 200 people. This size, which is still present today in contemporary communities and organizations (such as work and military organizations), is the maximum that still allows stable maintenance of interpersonal relationships. In five experiments - one of them on members of Sozioland - we confirmed this hypothesis: The level of fear of a disease that kills 100 people was consistently higher than of a disease that kills 10 people, but not different than the level of fear of a disease that kills 1,000 people. This result suggests that the extinction of one’s immediate group is enough to provoke dread. Killing more people is not ‘necessary’ to increase fear. We have also found support for our second hypothesis, namely that risks killing over a prolonged period of time will incite less fear than those that kill the same number of people within a short time span. As predicted in our third hypothesis, this pattern was specific for the context of risks: Perceived size of context-free numbers and monetary amounts continued to increase with actual number size. In sum, our results show that mechanisms that trigger dread might have an evolutionary basis.