
Chimps Favor Crystals, Hinting at Ancient Cognitive Bias
Enculturated chimpanzees at a Madrid sanctuary repeatedly preferred crystals over ordinary rocks, inspecting their transparency and shape, and even sorting them into groups. The behavior mirrors perceptual biases that may have guided early human cognition toward recognizing symmetry and Euclidean form, potentially influencing the development of symbolic thought—though the study is small and requires replication in wild apes.













