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We Continue to Sense Danger Even When Threats Decrease

New research finds when a situation gets less dangerous, we fail to perceive the positive shift.

Crime rates have declined dramatically in recent years, but Americans believe the opposite is true. The reasons for this misperception presumably include the rhetoric of the president, and the prevalence of crime on local television news.

But new research suggests a more basic cause: We are terrible at recalibrating our initial perceptions of a situation.

It presents evidence that, once we size up the circumstances we face, we doggedly stick with that initial assessment, even when it no longer reflects the facts on the ground. That means when the number of threatening faces we see decreases, we compensate by perceiving neutral faces as threatening.

"The majority of people believe that the world is getting worse," writes a research team led by Harvard University psychologists David Levari and Daniel Gilbert. Our skewed sense of reality "may be one source of that pessimism," they write in the journal Science.

The researchers provide evidence of this surprisingly robust phenomenon in seven experiments. In the first, 21 Harvard students were shown a computer screen featuring a series of dots, which ranged in color from pure blue to purple. Each stayed on the screen for only half a second; after seeing it, they indicated whether or not they considered it blue.

Half the students were randomly assigned to the "stable" condition, meaning that the dots were randomly selected from both sides of the color spectrum. The others were placed in the "decreasing" condition, meaning the percentage of pure-blue dots gradually but markedly decreased over the course of 1,000 trials.

"When the prevalence of blue dots decreased," the researchers report, "participants' concept of 'blue' expanded to include dots that it had previously excluded." They expected to see blue dots, so they saw blue dots.

Follow-up studies showed this remained true "even if participants were told the blue dots would definitely decrease; when the decrease happened very suddenly; and when participants were given monetary incentives to report the decrease."

Another experiment tested whether this bias applied to real-world situations. The participants, 48 Harvard students, looked at a series of human faces and judged each as to whether it was threatening.

The researchers took images of clearly threatening and non-threatening faces and morphed them into 60 computer-generated images that conveyed gradations of threatening expression. Once again, half saw an unchanging mix of faces, while others gradually saw fewer and fewer threatening ones.

The results replicated those of the blue-dot tests. Over 800 trials, "when the prevalence of threatening targets decreased, participants' concept of threat expanded to include targets that it had previously excluded," the researchers report.

"These results have sobering implications," Levari and his colleagues conclude. "Many organizations and institutions are dedicated to identifying and reducing the prevalence of social problems. Our studies suggest even well-meaning agents may sometimes fail to recognize the success of their own efforts."

The faux threatening faces are particularly problematic, given that fear of crime can prompt support for unneeded or even counterproductive laws. Sometimes, it seems, you really can't believe your lyin' eyes.