Activity adequacy mindsets and their effects on health and wellbeing
Keywords: Business.

It is widely recognized that physical activity is critical for individuals' health and longevity. Tremendous resources are being devoted to initiatives aiming to increase people's physical activity levels, including public health campaigns, workplace health programs, and the development of health technology. However, this focus on physical activity behavior has obscured another, related factor that may powerfully shape health and wellbeing----that is, mindsets about physical activity. This dissertation shines a light on individuals' mindsets about the adequacy and health consequences of their level of physical activity (activity adequacy mindsets). It investigates the causes, consequences, and mechanisms of action of these mindsets, and it develops interventions to help individuals adopt beneficial mindsets and thereby improve their health and wellbeing. In Chapter I, I introduce the entire dissertation. I review the literature on mindsets and health, and introduce the novel construct of activity adequacy mindset. I then describe and provide context for five open questions that are critical to understanding and harnessing activity adequacy mindsets. First, do activity adequacy mindsets causally influence health and wellbeing, independently of actual activity? Second, do these mindsets have long-term consequences? Third, what are the real-world sources of activity adequacy mindsets? Fourth, what are the processes explaining how activity adequacy mindsets affect health and wellbeing? And fifth, how can we harness activity adequacy mindsets to promote people's health and wellbeing at scale? The following chapters address each of these open questions in turn. In Chapter II, I investigate whether activity adequacy mindsets may influence important long-term outcomes. Specifically, I examine whether individuals' perceived levels of physical activity compared to others----a proxy for activity adequacy mindset----predict mortality. Survival analysis of data from three nationally representative samples with a total sample size of 61,141 U.S. adults and follow-up periods of up to 21 years shows that perceived physical activity does indeed predict mortality, controlling for actual amounts of physical activity. In Chapter III, I test if physical activity guidelines may represent one important real-world source of activity adequacy mindsets. Two experimental studies show that guidelines prescribing a relatively high amount of physical activity (such as the current official guidelines) may unintentionally induce negative activity adequacy mindsets, and thereby undermine individuals' self-efficacy, physical activity behavior, and health. In Chapter IV, I present a longitudinal field experiment leveraging the sensing and feedback capabilities of Apple Watch to study the causal effects of activity adequacy mindsets on health and explore the processes that may explain how mindsets create these effects. Additionally, I develop and test a scalable meta-mindset intervention designed to empower individuals to consciously adopt more beneficial mindsets and thereby improve their own health and wellbeing