Whither the Third Quarter Phenomenon?

INTRODUCTION: In 1991, Bechtel and Berning proposed that a decrement in morale and well-being affects people working in isolated and confined environments during the third quarter of their mission. Studies conducted during such conditions have suggested that whereas some people may experience such a phenomenon, it is not a typical occurrence in space or space simulation environments. Possible reasons for varying outcomes include demand characteristic bias, individual personality traits, training omissions, experimental methodological issues, and the impact of mission events on crewmember well-being. Research related to a future Mars expedition needs to investigate the impact of these factors.Kanas N, Gushin V, Yusupova A. Whither the third quarter phenomenon? Aerosp Med Hum Perform. 2021; 92(8):689691.