In 2025, researchers published a fascinating study in the journal npj Mental Health Research exploring whether unexpected events could make people more likely to help others.
The experiment took place on the Milan Metro in Italy and involved 138 observation sessions.
During the experiment, a female researcher wearing a prosthetic pregnancy belly boarded crowded trains and stood among seated passengers.
Researchers observed how many people voluntarily offered her their seats.
In some sessions, another researcher dressed as Batman also entered the train through a different door, approximately three metres away.
The results were surprising.
When Batman was absent, only 37.66% of observations involved someone offering the woman a seat. When Batman was present, that figure jumped to 67.21%.
Even more interestingly, approximately 44% of the people who offered their seats in the Batman sessions later said they hadn't even noticed him.
Researchers suggested that an unexpected sight might interrupt people's everyday routines, make them more attentive to their surroundings, and increase their willingness to help others.
