Dehumanized Perception: A follow-up report

In August last year, I put up a post titled "The Science of Hating Homeless People," that looked at research by Dr. Lasana T. Harris, a professor of Psychology and Neuroscience at Duke University, and Dr. Susan T. Fiske, a professor of Psychology and Public Affairs at Princeton.

From a series of research projects, led by Harris & Fiske, it was determined that prestige-university students did not recognize homeless people and addicts as being humans.  The evidence of this came from activity in select areas of the students’ brains that did or did not occur. The students registered disgust [as determined by brain activity] when pictures of homeless people or addicts where flashed on a screen in front of them.  The verbiage used to describe what registered in the students’ minds was that homeless people and addicts were “dehumanized,” that is, that they were not experienced as being human.

It has been a curious thing to me that it could be possible for people to not recognize homeless people and addicts as being human. After all, they look human: they have arms and legs and a head and a torso like humans. They talk; they walk; and move around and act like humans. They are, to my mind, as easy to identify as human as any other category of people. So, “What the hell is going on here?” I have to wonder.

The research by Harris & Fiske consisted of still photos flashed in front of each student, while a magnetic resonance imaging device focused on select areas of the students' brains. Whereas the students' brain activity showed that they interpreted other categories of people as being human, homeless people and addicts were interpreted to be some sort of "thing." Whatever the pictures displayed of all the people flashed before the students, it would seem to me the figures in the photo simply had to be recognizable people: HUMANS. They weren’t cats or dogs or apple trees or snow-topped mountains or stacks of hay or thumbtacks or racecars. They were human beings, something that we are prone to recognize extremely easily.

Oliver Sachs, in 1990, wrote a non-fiction book titled “The Man who Mistook his Wife for a Hat.” In his book about  neurological disorders of some of his patients, Sachs showed that it is possible for a person with a very troubled brain to make some stunning mistakes. Curious to me that prestige-university students, whom we must suppose have sound brains that operate marvelously well, could ever fail to see that a picture of a human, or group of humans, are human.

In an article in the Duke University student newspaper in 2011, "A Brain's Failure to Appreciate Others May Permit Human Atrocities," Harris and Fiske explain the circumstance of people who dehumanize others:

...a person can become callous enough to commit human atrocities because of a failure in the part of the brain that's critical for social interaction. A new study by researchers at Duke University and Princeton University suggests this function may disengage when people encounter others they consider disgusting, thus "dehumanizing" their victims by failing to acknowledge they have thoughts and feelings.

This shortcoming also may help explain how propaganda depicting Tutsi in Rwanda as cockroaches and Hitler's classification of Jews in Nazi Germany as vermin contributed to torture and genocide, the study said.

"When we encounter a person, we usually infer something about their minds. Sometimes, we fail to do this, opening up the possibility that we do not perceive the person as fully human," said lead author Lasana Harris, an assistant professor in Duke University's Department of Psychology & Neuroscience and Center for Cognitive Neuroscience.

What's especially striking, the researchers said, is that people will easily ascribe social cognition -- a belief in an internal life such as emotions -- to animals and cars, but will avoid making eye contact with the homeless panhandler in the subway.

"We need to think about other people's experience," Fiske said. "It's what makes them fully human to us."

The duo's previous research suggested that a lack of social cognition can be linked to not acknowledging the mind of other people when imagining a day in their life, and rating them differently on traits that we think differentiate humans from everything else.

This latest study expands on that earlier work to show that these traits correlate with activation in brain regions beyond the social cognition network. These areas include those brain areas involved in disgust, attention and cognitive control.