"Everyone Else Is Doing It":
Relations Between Bias
in Base-Rate Estimates
and Involvement in
Janis E. Jacobs
Kristen E. Johnston
The Pennsylvania State University
"Everyone else is doing it" is a well-known refrain to parents. It is typically used by their offspring as evidence that engaging in a particular behavior or activity is normative (and therefore should be allowed). Although most parents are not swayed by such entreaties (they know that not everyone else is doing it), are the adolescents aware of the fallacy? In other words, are adolescents' perceptions of the relevant base rates accurate and their use of the phrase, "everyone else," is simply a strategy employed to wear down their parents or do they really believe their own rhetoric?
Several decades of research have pointed to the importance of the use of base rates to make accurate social judgments (e.g., Dawes, 1988; Kahneman, Slovic, & Tversky, 1985) because in many situations, individuals must rely on their estimates of the base rates of behaviors when making inferences about others or when deciding about future behaviors for themselves. Decision-making skills often involve a combination of base-rate judgments and the use of anecdotal heuristics (Zukier & Pepitone, 1984), and it is generally agreed that the use of base rates is associated with more accurate judgments and predictions (Hasher & Chromiak, 1977; Swann, 1984).
Actual base rates, however, are rarely available in most real-life social situations (Bar-Hillel & Fischhoff, 1981; Kruglanski, 1989). Jacobs, Greenwald, and Osgood (1995) suggested that perceivers must rely on their own estimates of the base rates of social behaviors and attitudes from the events