Pygmalion effect (Rosenthal effect)

Biological Parallel

When researchers expect certain rats to be 'maze-bright,' those rats perform better—not through genetics but through handler behavior. Subtle cues (more gentle handling, encouragement) create self-fulfilling prophecy. Domestication reveals the same: animals treated as cooperative become cooperative across generations (silver fox experiment). Expectations shape behavior through micro-interactions invisible to the expectant party. Biology demonstrates that observation is never neutral when observers have agency.