Check for updates Research Report aps ASSOCIATION FOR PSYCHOLOGICAL SCIENCE Wearing a Bicycle Helmet Can Increase Risk Taking and Sensation Seeking in Adults Tim Gamble and Ian Walker Department of Psychology, University of Bath Psychological Science 2016, Vol. 27(2) 289-294 Cc @ The Author(s) 2016 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0956797615620784 pss.sagepub.com SSAGE Abstract Humans adapt their risk-taking behavior on the basis of perceptions of safety; this risk-compensation phenomenon is typified by people taking increased risks when using protective equipment. Existing studies have looked at people who know they are using safety equipment and have specifically focused on changes in behaviors for which that equipment might reduce risk. Here, we demonstrated that risk taking increases in people who are not explicitly aware they are wearing protective equipment; furthermore, this happens for behaviors that could not be made safer by that equipment. In a controlled study in which a helmet, compared with a baseball cap, was used as the head mount for an eye tracker, participants scored significantly higher on laboratory measures of both risk taking and sensation seeking. This happened despite there being no risk for the helmet to ameliorate and despite it being introduced purely as an eye tracker. The results suggest that unconscious activation of safety-related concepts primes globally increased risk propensity. Keywords risk taking, sensation seeking, social priming, bicycling, protective equipment, behavior change, open data Received 9/8/15; Revision accepted 11/12/15 People's perceptions of safety influence their risk taking. This phenomenon, studied under such rubrics as risk compensation (Adams & Hillman, 2001), risk homeosta- sis (Wilde, 1998), and risk allostasis (Lewis-Evans & Rothengatter, 2009), is typified by people taking increased risks when using protective equipment (Adams, 1982) or at least reducing their risk taking when protective equip- ment is absent (Fyhri & Phillips, 2013; Phillips, Fyhri, & Sagberg, 2011). Behavioral adaptation in response to safety equipment has been reported in studies examining drivers operating a vehicle with and without built-in safety devices (Sagberg, Fosser, & Sætermo, 1997), chil- dren running obstacle courses with and without safety gear (Morrongiello, Walpole, & Lassenby, 2007), and bicyclists descending a steep hill with and without hel- mets (Phillips et al., 2011). Work to date has been based on the assumption that people respond only to safety measures of which they are aware-an idea encapsulated in Hedlund's first rule of risk compensation: "If I don't know it's there, I won't compensate for a safety measure" (Hedlund, 2000, p. 87). Moreover, in research to date, the risk-taking behavior has been in the same domain as the safety measure (e.g., studies of seat-belt use in driving speed; Janssen, 1994). Here, we changed both these approaches. First, we induced people to wear a helmet without their necessar- ily being aware they were wearing safety equipment: Participants were (falsely) told they were taking part in an eye-tracking study so we could exploit the fact that the head-mounted eye-tracking device we employed comes with both a bicycle helmet and a baseball cap as its standard mounting solutions. At