The study, funded by Britain's Economic and Social Research Council, questions a long-held belief that people quickly put anyone they meet into a limited number of social categories such as female or male; Asian, Black, Latino or White; and young or old.
Kimberly Quinn at the University of Birmingham found people "see" faces in multiple ways that factor in to whether and how people categorize others.
"How we perceive faces is not just a reflection of what's in those faces," Quinn said in an ESRC release Friday. "We are not objective; we bring our current goals and past knowledge to every new encounter. And this happens really quickly -- within a couple of hundred milliseconds of seeing the face."
Categorization depends on more than just the physical features of the face in front of us, she said, but includes other information as well -- such as whether the other person is already known and whether the person is believed to share other important identities with us.
Although social categories are used to gather information on faces, these can be easily undermined, she said, so people will reject simple stereotypes when something about the situation alerts them to the fact the stereotype does not tell the whole story.
Quinn's findings suggest facial perception focuses on "coarse" information that is easy to detect, but then immediately starts to include more fine-grained processing as time elapses.
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