The instability of the two cultural attractors found within the Renaissance

Cultural attractor theory proposes that recurrent psychological biases shape the persistence and transformation of cultural traditions. Portraiture offers a unique test case, embedding perceptual cues that reflect both individual choices and collective conventions. Using automated facial analysis, we examined more than 3200 digitized portraits across four corpora—Renaissance secular portraits, Renaissance religious paintings, post-Renaissance portraits, and Japanese ukiyo-e—to examine two renowned cultural attractor: direct eye gaze and the left cheek bias. Results replicated previous finding of a Renaissance shift toward direct gaze, but this trend did not persist after 1600—the aggregate frequency of direct gaze declined—suggesting the attractor was not stable. The directional trend toward direct gaze was likewise absent in religious paintings and ukiyo-e. The left cheek bias was strong in the Renaissance, weakened in later Europe, and showed no significant temporal change in ukiyo-e. Across analyses, sitter fame-but not gaze-predicted cultural visibility. By applying a unified machine-learning approach, this study illustrates that previously claimed universal cultural attractor for preferences for direct eye-gaze and the left-cheek bias may be more unstable than often assumed, with their strength possibly tracking the changing socio-ecological functions of portraiture instead, and highlights the importance of incorporating temporally and geographically diverse corpora when analyzing cognitive fossils such as portraiture.