Why we tend to trust strangers without even seeing them

A new study has revealed that human brains have the capability to judge the trustworthiness of a face even when we cannot consciously see it.

According to the study, that the brain automatically responds to a face's trustworthiness before it is even consciously perceived, which might be the reason behind why we form spontaneous judgments of other people that can be largely outside awareness.

The researchers focused on the workings of the brain's amygdala, a structure that is important for humans' social and emotional behavior. Previous studies have shown this structure to be active in judging the trustworthiness of faces. However, it had not been known if the amygdala is capable of responding to a complex social signal like a face's trustworthiness without that signal reaching perceptual awareness.

Jonathan Freeman, from New York University's Department of Psychology, said that the findings provide evidence that the amygdala's processing of social cues in the absence of awareness may be more extensive than previously understood and the amygdala is able to assess how trustworthy another person's face appears without it being consciously perceived.

the researchers found that specific regions inside the amygdala exhibited activity tracking how untrustworthy a face appeared, and other regions inside the amygdala exhibited activity tracking the overall strength of the trustworthiness signal (whether untrustworthy or trustworthy)-even though subjects could not consciously see any of the faces.

The study was published in the Journal of Neuroscience.