Research has revealed that, when we speak in a foreign language, we can be more ruthless in making snap decisions. In mock scenarios, bilinguists were more willing to push someone off a bridge, to save five others, if the options were posed in a foreign tongue.
Our native language, it seems, brings up childhood memories and emotions about right and wrong. But, when we learn to speak in an academic setting, our moral compass is influenced by facts, not feelings.
Research: Scientific American 2016