Judging people can be a tricky business. Racing to conclusions about someone can lead to false assumptions and is a decidedly closed way to view the world, yet trusting everyone until proven guilty may lead to some sketchy situations. Regardless, the current zeitgeist encourages restraint from criticism and holding back from judging people we don’t know.

But now a team of scientists from New York University is shedding light on how we form snap judgments and why going with your gut might be a good thing in some situations.

The researchers looked at the how the brain’s amygdala — an area that is involved in our social and emotional behavior — responds to complex cues about people. What they discovered is that our brains can assess the trustworthiness of a face, without the signals even reaching perceptual awareness.

“Our findings suggest that the brain automatically responds to a face’s trustworthiness before it is even consciously perceived,” explains Jonathan Freeman, an assistant professor in New York University’s Department of Psychology and the study’s senior author.

“The results are consistent with an extensive body of research suggesting that we form spontaneous judgments of other people that can be largely outside awareness,” adds Freeman, who conducted the study as a faculty member at Dartmouth College.

They determined this through a pair of experiments in which researchers monitored participants’ amygdalae while they looked at images of faces.

The faces included photographs of strangers’ mugs as well as faces that were manipulated to tweak the “trust” cues. Research has shown that higher inner eyebrows and pronounced cheekbones are viewed as trustworthy while lower inner eyebrows and shallower cheekbones are not. They had a test group examine all of the faces and rate them on trust. The subjects strongly agreed on the level of trustworthiness expressed by each face.

In the experiment, a new set of participants were shown the same photos while having their brains scanned. However they were shown the faces for only milliseconds. In addition, the subjects were then shown an irrelevant “mask” image that worked to stop the brain from further processing the face and to prevent the image from reaching awareness.

In the second experiment, the researchers monitored amygdala activity as it responded to a fully continuous spectrum of trustworthiness.

In both experiments, the scientists found that certain parts of the amygdala tracked how untrustworthy a face appeared, and other regions inside the amygdala tracked the overall strength of the trustworthiness signal (either low or high) even though participants did not consciously see the faces.

“These findings provide evidence that the amygdala’s processing of social cues in the absence of awareness may be more extensive than previously understood,” observes Freeman. “The amygdala is able to assess how trustworthy another person’s face appears without it being consciously perceived.”

Joe Navarro, retired FBI special agent and author of "Dangerous Personalities" confirms this idea that we have a keener sense of judgment than meets the eye.

"Whatever you want to call it, it is often an intangible feeling that we have that something isn't right, that something is odd or weird,” he tells Rodale News. “It can be about a location in a darkened neighborhood or someone we meet for the first time."

If your hair stands up, your hands start to sweat, your throat becomes dry or your heart starts pumping when someone walks in the room, it's time to tune into your body's way of quietly telling you something's wrong, Navarro explains.

"The first thing is to recognize your feelings," he says. Further establishing the idea that sometimes listening to your gut is the way to go, regardless of what we’re told about judging people.

Related on MNN: