Posing popes: A question of left and right

Area of Science:

• Psychology
• Art History
• Sociology

Background:

• Facial asymmetry, specifically left cheek bias, is common in portraits, often linked to emotional expressivity.
• Papal portraits offer a unique, continuous dataset for studying facial posing biases over centuries.

Purpose of the Study:

• To investigate the temporal continuity of the left cheek bias phenomenon in papal portraits.
• To analyze posing trends in papal portraits from the Vatican archives.

Main Methods:

• Quantitative analysis of 266 papal portraits from the Vatican website.
• Categorization of portraits based on left cheek bias, right cheek bias, or symmetry.
• Temporal analysis dividing portraits into five-century intervals.

Main Results:

• No significant overall left cheek bias was detected across all papal portraits (51% leftward, 46% rightward, 3% symmetrical).
• Earlier centuries showed an even distribution of left and right cheek bias.
• The last five centuries exhibited a trend towards leftward bias, with the most recent 12 popes exclusively displaying leftward bias.

Conclusions:

• The historical prevalence of left cheek bias in portraits is not consistently observed in papal imagery across all periods.
• A notable increase in leftward bias among recent popes suggests a potential influence of evolving societal roles and perceived emotional expressivity.
• The statistically improbable concentration of leftward bias in the last 12 popes warrants further investigation into socio-historical factors.