Harmful Compared to What? The Problem of Gaming and Ill-defined Causal Effects

There has been much concern regarding potential harmful effects of video game play in the past 40 years, but there has been limited progress in understanding its causal role. In this paper we take a step back and discuss the basic requirements for identifying causal effects of video game play and argue that most research to date has not satisfied these assumptions. In particular, we discuss the consistency assumption and causal inference with compound exposures, that is, exposures with multiple relevant variants that affect outcomes in different ways. Not only does exposure to video games entail multiple different things, but not playing video games is equally ambiguous. Without a well-defined causal contrast, research investigating the effects of video game play cannot be translated into actionable public health policies. We also argue that policies or interventions that target games should be compared to other interventions aimed at improving the same outcomes, such as established interventions for known determinants of health and well-being or other relevant outcomes, like sleep or leisure-time sedentary behaviors.