Wilkinson et al. BMC Public Health 2012, 12:332 http://www.biomedcentral.com/1471-2458/12/332 Background Sensation seeking is a personality trait that takes the form of seeking novel, varied, complex, and intense sensations and experiences and the willingness to take physical, social, legal, and financial risks in order to experience this sensation [1]. Sensation seeking tendencies tend to manifest during adolescence [1] and are associated with both health- compromising behaviors (e.g., experimentation with cigarettes) [2] and health-enhancing behaviors (e.g., physical activity) [3]. Engaging in health-enhancing behaviors, like physical activity, may protect adolescents at risk for health compromising behaviors, such as smoking [4]. Accordingly, how sensation seeking tendencies are exhibited in youth have long-term implications for both cardiovascular disease and cancer prevention, as the onset of these health behaviors occurs during adolescence and tracks into adulthood [5-8]. While there is a clear genetic component to sensation seeking behaviors [9], how sensation seeking tendencies manifest is, in large part, a function of the social context [10,11]. For immigrant youth, the social context is defined by experiences of on-going acculturation (for many, identification with a new and dominant culture) and associated shifting social and behavioral norms [12]. As immigrant youth mature, they may encounter social situations that facilitate experimentation with cigarettes and/or provide more opportunities to be physically active. For example, among Mexican origin adolescents, smoking rates increase with longer residence in the United States (U.S.) [13], and among Latino youth in general, increased linguistic acculturation is associated with higher levels of physical activity [14,15]. As a result of living in the U.S., normative expectations regarding smoking and physical activity may be challenged, while strong family ties may bind youth to traditional norms and beliefs which prohibit smoking and reduce physical activity in particular among girls [16,17]. As immigrant youth with high sensation seeking tendencies acculturate, and the norms that previously governed their behavior are replaced, these youth may feel released to engage in and adopt behaviors that would have been prohibited in their country of origin. In addition, the relationships among acculturation, experimenting with cigarettes and being physically active may vary by gender among youth of Mexican origin, as traditionally, gender roles and norms tend to be more clearly defined in Mexico compared to the U.S. [18,19]. Immersion in a culture with less defined roles may result in less extreme gender differences in sensation seeking behaviors, as girls would be more likely to participate in these behaviors the more they become acculturated to the U.S. One study suggests that, for Latino youth more generally, the effect of acculturation on increased smoking is more pronounced for girls than for boys [20]. Page 2 of 11 Less information exists as to the possible gendered nature of the association between acculturation and physical activity. To date, researchers have explored the relationship between acculturation and both physical activity and smoking, as well as relationships among sensation seeking tendencies and both behaviors. However, to the best of our knowledge no studies have examined the 1) association between linguistic acculturation and sensation seeking tendencies and 2) the independent and combined associations between gender and sensation seeking on physical activity and smoking, across levels of linguistic acculturation. Thus, the purpose of the current analysis is to evaluate relationships between sensation seeking and physical activity and between sensation seeking and experimenting with cigarettes among a cohort of Mexican origin youth residing in the U.S. with different levels of linguistic acculturation. We hypothesize that 1) participants who are more acculturated to the U.S. will report more physical activity (i.e. being physically active for at least 60 minutes on five or more days a week) and cigarette experimentation than the less acculturated; 2) the influence of gender on experimenting with cigarettes and being physically active for at least 60 minutes on five or more days a week will decrease as levels of linguistic acculturation increase, even after adjusting for sensation seeking tendencies; and 3) the association of sensation seeking with the two behaviors will vary across levels of linguistic acculturation, after adjusting for the effect of gender. Methods Study design Our data were derived from Mexican origin adolescents who are participants enrolled in a prospective study of smoking behavior that began in 2005. Participants for our study were drawn from a large population-based cohort launched in 2001 by the Department of Epidemiology at The University of Texas M. D. Anderson Cancer Center. Participants in this cohort, called the Mexican American Cohort Study (MACS), are all self-identified adults of Mexican origin. Households were initially recruited into the MACS via probability random-digit dialing, door-to-door recruitment, intercepts (i.e. health fairs, community events, etc), and networking approaches. Results from these pooled recruitment methods indicated no significant differences in populations with respect to language preference, country of birth (Mexico or U.S.), years living in the U.S. among those born in Mexico, and household income [21]. A detailed description of the MACS data collection has been published elsewhere [22]. Briefly, Mexican origin adults who agree to join the MACS, provide informed consent and complete an interview-administered survey in their home, in either English or Spanish. The survey assesses demographic char- acteristics, health risk behaviors, occupational exposures,