Cross-cultural analysis reveals evolution and persistence of body-based measurement systems

Body-based units of measure have cognitive and behavioral advantages over standardized measurement systems, according to a new cross-cultural analysis of the use of body-based measurement in more than 180 cultures worldwide, particularly in the design of ergonomic technologies. The findings reveal new insights into body-based measurement as a cultural phenomenon and may help explain the long-term persistence of their use for centuries after the emergence of standardized measurement systems were invented. The ability to measure things plays a central role in how humans understand and interact with the surrounding world and are important drivers in cultural complexity and technological evolution. Today, interchangeable units of measure are ubiquitous in the modern world and permeate every aspect of daily life. Worldwide, it's thought that many early standardized measurement systems evolved from body-based units of measure – measurement units that are determined by using components of the human body, such as the length of forearm and hand (cubit) or width of two outstretched arms (fathom). However, despite their importance in cultural and technological evolution, body-based measurements as a cultural phenomenon remain understudied and poorly understood. Using the Human Relations Area Files (HRAF) ethnographic database, Roope Kaaronen and colleagues identified the development and use of body-based measurements in 186 cultures worldwide, revealing both similarities and diversity in the use of measurement units based on the human body. According to the findings, variations of the fathom, handspan, and cubit were most frequent and exhibited striking cross-cultural similarities. Kaaronen et al. also discovered that body-based units were especially common in the design of ergonomic technologies like clothing, skis, kayaks, or bows, for example. The analysis revealed that body-based units were still used worldwide thousands of years after the emergence of standardized units and were, in some instances, superior to standard units of measurement. The authors argue that the shift from body-based measurement systems to standardized systems could reflect a larger break in human cultural evolution due to increased focus on industrial production. Consequently, traditional units of measure may be threatened by the broader cultural extinction event driven by globalization, industrialization, and colonization, write Kaaronen et al. In a related Perspective, Stephen Chrisomalis highlights the limitations of the study and its findings. "Datasets such as HRAF, used by Kaaronen et al., are skewed toward ethnographically known societies from the 19^th and 20^th centuries," writes Chrisomalis. "Future studies must employ cognitive cross-cultural research that is sensitive to how technologies change across time, not merely synchronic patterns in the modern world."