(Inside Science) -- Are humans fundamentally wicked, prone to choose immoral acts by default? Philosophers and theologians have debated this question for centuries. Now, a scientific study suggests a simple answer: No.

By default, people exclude immoral acts from their array of choices, even viewing them as physically impossible, according to a study recently published in Proceedings of the National Academy of Sciences. The researchers presented people with various scenarios, such as that of a man whose car breaks down while he is on his way to catch a flight. Then, they asked people to judge whether different reactions were possible or impossible. They gave some people time to consider their answers, while forcing others to make judgments within 1.5 seconds.

People generally rated ordinary actions, such as hailing a taxi or booking the next available flight, as possible, and ludicrous ones like teleporting to the airport as impossible, regardless of how much time they had. But people under time pressure often rated morally questionable actions, such as sneaking onto public transit, as impossible. People who had more time generally rated such actions as possible. These findings are in line with previous research showing that young children often view immoral acts as impossible, even saying that "magic" would be needed to accomplish them.

In a follow-up experiment, the researchers asked people to make other judgments, such as whether the person in the story may, could or ought to perform the action. Under time pressure, people tended to consistently reject some actions and consistently accept others, regardless of the actual question asked. For example, people tended to say that all the things a person shouldn't do, they also couldn't do.

According to the researchers, the findings suggest that people initially filter the options available to them into only two categories: options worth considering, and those that are off the table. By default, immoral actions go into the off-the-table category, just like actions that violate physical laws. Thus, in some sense, doing what's wrong takes more thought than doing what's right.