This special issue marks the 50th anniversary of the landmark Pygmalion experiment (Rosenthal & Jacobson, 1968). It offers contributions from across the globe, attesting to universal features of teacher expectancy effects. Reviews of this history underscore controversy, advances, and few intervention studies. Empirical studies emphasise teacher expectancy effects at group, classroom, and school levels, contrast expectation measures, and explore longitudinal and developmental perspectives, advancing the field. Despite headway, I argue that the field's contested history has stifled its fullest investigation. Conclusions drawn -- not replicable, small and dissipating effects, and largely accurate teacher expectations -- have underestimated Pygmalion's power and limited investment in intervention research to promote "positive" educational prophecies, especially for students placed at the margins. It is time for a greater articulation of the conditions under which expectancy effects are most powerful. It is also time to apply our tremendous knowledge towards the design and evaluation of positive expectancy interventions.