Methods / Methodology
FWHR was measured using the following protocol:
1. Leader identification
Leader names and tenures use "Identifying Ideologues: A Global Dataset on Political Leaders, 1945–2020". Heads of government are included. Herre B. Identifying Ideologues: A Global Dataset on Political Leaders, 1945–2020. British Journal of Political Science. 2023;53(2):740-748. doi:10.1017/S0007123422000217.
2. Image collection
Standardized frontal photographs were hand selected to fit requirements. If no photographs were suitable, data was omitted. Images were accepted only if the face was unobstructed, approximately frontal (<15° rotation), and of sufficient resolution. Future tasks could include collecting multiple photos for a more robust dataset.
Method based on, though not directly replicated, Ross A Miller, Facial Metrics, Aggression, and the Use of Military Force, Foreign Policy Analysis, Volume 18, Issue 4, October 2022, orac023, https://doi.org/10.1093/fpa/orac023.
3. FWHR measurement
FWHR is defined as bizygomatic width divided by upper facial height (distance from brow line to upper lip). Calculations made using Python and the face_recognition package, using interaction methods listed by Ties de Kok, former Assistant Professor at the University of Washington, and exported to a .csv file using Claude AI model Sonnet 4.6 to automate the process.