A research team from Spain and the U.S. conducted a series of experiments with university students in five countries who had learned a second language during childhood.
In one experiment, 317 subjects from the U.S., South Korea, France and Israel were asked to imagine an oncoming train about to strike five people on a footbridge hanging low above the track because of the weight on it. The choices were doing nothing, which would result in the deaths of all five people, or taking the logical, but perhaps emotionally difficult, decision to push a heavy man off the bridge, and thereby saving four.
Half of the subjects in each country were instructed to answer the question in their native language and half in their acquired language. Among the participants speaking an acquired language, 33% opted to push the man. But when people were speaking their native tongue, only 20% chose that option.
The same question was posed to 725 participants in Spain—397 were native Spanish speakers who spoke English and 328 were native English speakers who spoke Spanish.
When answering in their native tongue, 18% chose pushing the man off the bridge. When using the learned language, 44% chose to push the man.
Subjects who were more proficient in a foreign language made decisions that resembled native-language speakers, further experiments showed.
Caveat: None of the Korean participants chose to push the man to his death, possibly due to cultural values, researchers said.