People typically say they are invoking an ethical principle when they judge acts that cause harm more harshly than willful inaction that allows that same harm to occur. That difference is even codified in criminal law. A new study based on brain scans, however, shows that people make that moral distinction automatically. Researchers found that it requires conscious reasoning to decide that active and passive behaviors that are equally harmful are equally wrong.For example (see below), an overly competitive figure skater in one case loosens the skate blade of a rival, or in another case, notices that the blade is loose and fails to warn anyone. In both cases, the rival skater loses the competition and is seriously injured. Whether it is by acting, or willfully failing to act, the overly competitive skater did the same harm."What it looks like is when you see somebody actively harm another person that triggers a strong automatic response," said Brown University psychologist Fiery Cushman. "You don't have to think very deliberatively about it. You just perceive it as morally wrong. When a person allows harm that they could easily prevent, that actually requires more carefully controlled deliberative thinking [to view as wrong]."