The “Batman effect” was demonstrated in an experiment where a woman who appeared to be pregnant boarded a train. When another experimenter entered dressed as Batman, passengers were far more likely to offer her their seat—67.2% did so compared with just 37.7% when Batman wasn’t present.
This Italian metro experiment, published in npj Mental Health Research, tested how an unexpected disruption could influence public kindness. A woman who appeared pregnant boarded a train, and commuters offered her a seat 37.7% of the time. When a researcher dressed as Batman entered through another door, that number jumped to 67.2%. Researchers suggested the bizarre sight may have jolted passengers out of their usual mental autopilot.