It is a common ethical dilemma set by philosophy professors – is it right to kill someone to prevent further deaths?
According to scientists the answer differs depending on your gender, with women less likely to commit murder because they have a stronger aversion to harmful action.
Researchers from the US, Germany and Canada analysed data that asked 6,100 people a range moral questions, including whether they would kill a young Adolf Hitler to stop the Second World War.
While men and women both calculated the consequences of their decision and computed how many lives might be saved, females found it harder to commit murder and were more likely to let Hitler live.
Another scenario imagined a member of a group hiding from soldiers being handed a crying baby. Participants were asked whether they would smother the child to save the group or let it live and be caught.
A hypothetical situation that did not involve murder questioned whether a person would be willing to have their daughter carry out sex work, so they could buy food for the rest of their starving family.
The difference in female and male responses is caused by emotional aversion to killing among women, according to the study published in the Personality and Social Psychology Bulletin.
Rebecca Friesdorf, a graduate student at Wilfrid Laurier University in Canada who co-authored the report, analysed 40 data sets from previous studies to produce her findings.
“Women seem to be more likely to have this negative, emotional, gut-level reaction to causing harm to people in the dilemmas, to the one person, whereas men were less likely to express this strong emotional reaction to harm," she told NPR.
Those who choose short-term harm for long-term gain are termed utilitarians. While individuals who are unable to countenance breaking moral conventions, in order to secure a more favourable future outcome, are called deontologists.
Women were found to be significantly more likely to be deontologists and agonised over their decisions, but men were slightly more likely to be utilitarians and were able to make a choice more quickly.
Deontology, based on Immanuel Kant’s theory of ethics, argues that rules should be followed and actions are more important than the consequences.
Whereas utilitarianism, espoused by philosophers Jeremy Bentham and John Stuart Mill, holds that the moral choice is the one that maximises utility; therefore it would be considered moral to kill one person to save two or more lives.