When a bad deed makes headlines, the first thing we want to know is whether the perpetrator did it “on purpose.” Intention matters in our moral judgments, as we intuitively realize and many studies confirm. Now studies suggest that this focus on the cause of an event can distort our understanding of the damage done—and knowing harm has been inflicted can even change the way we view the victims, ascribing them pain and consciousness when none might exist.

In a study published in July in Psychological Science, Princeton University psychologists Daniel Ames and Susan Fiske asked 80 study participants to read a vignette about a company CEO who had either accidentally or intentionally made a poor investment that resulted in lower pay for his employees. Those who thought the CEO had intentionally made the mistake estimated the harm done to his employees on a scale of 0 to 100 to be 39 percent larger than those who thought it was accidental.

In a follow-up experiment, 55 subjects read about a man who had either accidentally or intentionally diverted the flow of a river, causing a water shortage. Participants were then briefly shown an itemized list of the damages and were asked to estimate the total. Those who believed the diversion to be accidental estimated the damages accurately (on average, $2,753, as compared with the true total of $2,862), whereas those who thought the diversion had been done on purpose vastly overestimated the damages at $5,120. This psychological bias could have political implications: if governments systematically overestimate the damages done by intentional harms like terrorism, they might “leave fewer resources to combat other kinds of harms,” such as global warming, Ames says.

A different group of researchers at Harvard University and the University of Pennsylvania explored how intentional and unintentional acts affect our perception of those injured. In their study, published in June in Psychological Science, subjects read stories about a hospital nurse who unplugged the food supply of a patient in a persistent vegetative state named Ann in order to make money. Others read a similar story about a nurse who took good care of Ann. When subsequently asked about Ann's mental capacities, the subjects who had read about her as a victim said she was much more able to feel pain and was more consciously aware than did subjects who read the other story. When participants read a similar pair of stories in which the nurse had either intentionally or unintentionally cut off Ann's food supply, those who thought the act was intentional ascribed more mental faculties to Ann than did the others. In another series of experiments, Ann was described not as a human patient in a persistent vegetative state but as either a robot or a corpse. Again, subjects thought the entities were more mentally aware if they were victimized.

The findings have implications for our understanding of complex moral issues such as abortion. People may consider fetuses to be mentally aware because they think abortion is immoral—not the other way around. “People often have knee-jerk moral intuitions and only come up with explanations for these intuitions after the fact,” says co-author Adrian Ward, a psychologist now at the University of Colorado at Boulder. “Many times apparent causal reasoning is simply post hoc justification.”