This proposal relates to the call of the PSA PSA COVID-19 Rapid Project 003 data collection effort in Japan. To slow the transmission of COVID-19, governments around the world are asking their citizens to participate in social distancing, that is, to stay at home as much as possible. In most countries, individuals have some choice over whether or not they follow recommendations for social distancing. Thus, understanding how to best motivate social distancing has become a public health priority. This study tests, in a confirmatory manner, whether self-determination theory-guided message framing impacts people’s motivation to participate in social distancing. Specifically, we expect autonomy-supportive messages that help people understand the value of behavior change to a) increase ‘buy in’, or autonomous motivation, for social distancing, b) reduce feelings of defiance in response to those messages, and c) increase behavioral intentions to socially distance, relative to neutral and controlling messages. Further, we expect controlling messages that pressure people to change using shame, guilt, and demands, may backfire and a) decrease ‘buy in’ for social distancing, b) increase defiance, relative to the control condition, and c) reduce behavioral intentions to socially distance. We also expect ‘buy in’, or autonomous motivation, to explain why messages impact defiance and behavioral intentions. Exploratory tests will examine whether the effects of message framing on motivation, defiance, and behavioral intentions are moderated by culture, providing sufficient variability on this measure is obtained. This work has direct relevance for how public officials, health professionals, journalists, and others can communicate about solving this and future public health crises in ways that motivate people more effectively.