Say you're in the supermarket parking lot, holding your baby, bags of goods, and trying to open your car. A stranger walks up and says,"Here, let me hold your baby."Should you let him? According to a new New York University study, knowing whether or not to trust someone is so important that we can tell whether a face is trustworthy before we even consciously know it's there. The researchers knew from previous studies that people are fairly similar when it comes to how they judge a face's trustworthiness. They wanted to find out whether that would be true if people only saw a face for a quick moment -- an amount of time so short that it would prevent making a conscious judgment. To carry out their study, the researchers monitored the amygdala   of 37 volunteers while showing them 300 faces for 33 milliseconds each. Those faces had already been tested with a different set of 10 subjects, who saw them for much longer. In those earlier tests, people agreed about whether to trust each face. In this new study, fascinatingly, different parts of the amygdala lit up when a subject saw an untrustworthy face and a trustworthy one -- and it lit up more when the face in question was suspicious  . "Faces that appear likely to cause harm are suddenly tracked by the amygdala, so it could then quickly change other brain processes and make fast responses to people -- approach or avoid,"says Jon Freeman, the study's senior author."Our talents for making instant judgments could either come from birth or be learned from the social environment." So should you trust the guy in the parking lot? Your brain already knows. The amygdala lit up more clearly when people   .
came across a neutral face mask saw an untrustworthy face met a reliable person saw a familiar face