Video games are an indelible part of the modern American early life course. A 2008 Pew Research Center survey found 99% of males and 94% of females' ages 12-17 play video games [1]. Video gaming begins in early childhood and continues through adulthood [2,3]. Video games can be a modality for instruction and clinical intervention [4,5], when written for these purposes. Video games facilitate cognitive development [6]. They provide experiences of freedom and competence [7], opportunities to socialize, a sense of mastery, a medium for identity development, and -not least -fun [8]. Video games focus attention in ways that are palliative for and mood disorders [9-11].There are also potential "downsides" to video gaming. It is hard to ignore that there is some association between violent entertainment video games and aggression, although the strong and deterministic connections often made in popular discourse (e.g., in the aftermath of school shootings) are probably not supported by the evidence [12,13]. Another issue, which is explored in research [14], addressed in clinical settings [15,16], and identified with by players themselves [17], is subjective experiences of video game "addiction. " It is usually referred to as "Problem Video Game Play" (PVGP) or by similar terms to make it possible to discuss the phenomenon without implying a position about its status as a "real" addiction [18,19].Given these connections between video games and health, there is naturally some interest in how video gaming behavior develops over time. One concept that may be useful for addressing this question is "role incompatibility. " Role incompatibility has been used to explain the curvilinear relationship between substance use and age through the early life course [20]. From a role incompatibility perspective, substance use rises through adolescence and peaks during emerging adulthood as youth discover substances' potential for regulating negative emotions through usual adolescent experimentation and then use them explicitly for this purpose in emerging adulthood as a way of coping with stresses of identity development and experimentation with adult roles [21]. As emerging adults become young adults settled into adult roles with respect to school, work, and relationships, competing demands of those roles make previous use levels untenable and substance use decreases [22]. One study of the relationship between several video gaming indicators and age found a similar "role incompatibility" effect as several indicators of video game play (including PVGP) were observed to rise through childhood, peak in late adolescence, and either level off or fall through emerging adulthood, with an observed decrease in school/ work night video game play through emerging adulthood statistically explained by entry into higher education and full-time employment [23]. Consistent with expectations under a role incompatibility perspective, other studies found that middle school students intentionally use video games to regulate negative emotions and PVGP sign...