This study focuses on analysing the heights of 10,953 Korean men aged 20 to 40 years who were measured during the Joseon dynasty, the Japanese colonialisation period, and the contemporary period, the latter including both North and South Korea. This study thus provides rare long-term statistical evidence on how biological living standards have developed over several centuries, encompassing Confucianism, colonialism, capitalism, and communism. Using error bar analysis of heights for each historical sample period, this study confirms that heights rose as economic performance improved. For instance, economically poorer North Koreans were expectedly shorter, by about 6 cm, than their peers living in the developed South. Similarly, premodern inhabitants of present-day South Korea, who produced a gross domestic product (GDP) per capita below the world average, were about 4 cm shorter than contemporary South Koreans, who have a mean income above the world average. Along similar lines, North Koreans, who have a GDP per capita akin to that of the premodern Joseon dynasty, have not improved much in height. On the contrary, mean heights of North Koreans were even slightly below (by about 2.4 cm) heights of Joseon dynasty Koreans. All in all, the heights follow a U-shaped pattern across time, wherein heights were lowest during the colonial era. Heights bounced back to Joseon dynasty levels during the interwar period, a time period where South Korea benefitted from international aid, only to rise again and surpass even premodern levels under South Korea’s flourishing market economy.