What makes a face seem human? The answer, just like the question, is simultaneously facile and complex, according to Miami University psychology professor Kurt Hugenberg.
The simplest definition of what makes a face human, Hugenberg says, is an eyes-over-nose-over-mouth arrangement. This regular configuration helps us identify individual people more easily.
“If all houses were as similar as human faces,” Hugenberg says, “we’d never be able to tell our house apart from someone else’s. But because we are finely tuned to very small differences within faces, we can distinguish between them. Two people appear quite different, even though, objectively, they’re quite similar to one another.”
Hugenberg’s research team – including five graduate students and eleven undergraduate students – works to understand how people perceive humanity in others’ faces by asking participants to rate faces on certain characteristics.
The researchers show participants photographs of various faces and ask questions like, “How empathetic is this person?” and “How able is this person to solve complex logical problems?”
“These are characteristics only humans have, so the answers to those questions tell us a lot about the perceived humanity of a face,” Hugenberg says.
What Hugenberg and his team have found is that if the eyes-over-nose-over-mouth arrangement is altered in even the most basic way – by turning a face upside down, for instance – participants answer those questions in ways that reflect reduced perceptions of humanity.
“Remarkably,” Hugenberg says, “when you turn anything else upside down, it doesn’t lose its essential characteristics. If you turn a chimpanzee face upside down, it still seems equivalently chimp-like to people, but when you turn that human face upside down it loses some of its experienced humanity.”
But humanity – like beauty – is more than skin deep, and so, supported by an award of more than $500,000 from the National Science Foundation (NSF), Hugenberg and his colleagues, Indiana University’s Robert Rydell and Baruch College’s Steven Young, are now setting out to discover what goes on in the brains of people who view faces that violate the eyes-over-nose-over-mouth configuration.
They will use electroencephalography, or EEG, a technique in which electrodes are placed on the scalp to measure the electrical activity of neurons in the brain. “EEG measures temporal activation,” Hugenberg says, “so we’ll be able to see roughly where and exactly when different processes occur in the brain.”
Like with Hugenberg’s previous research this new work will involve a number of graduate and undergraduate students every step of the way, from planning and preparing experiments to collecting and then analyzing data, to preparing manuscripts. “This is work that never would, or even could, happen without them,” Hugenberg says.
Hugenberg gives special credit to his graduate students, Steven Almaraz, Jason Deska, Paige Lloyd, Kurt Schuepfer, and Taylor Tuscherer, who he says make the participation of his more junior students, Chris Culp, Saara Khalid, Zoebedeh Malakpa, Neema Mohammadi, Kelli Peterman, Bill Schauer, Monica Scicolone, Michaela Schukies, Evans Smalley, Kellen Smith, and Jason Weiss, possible. “Without the graduate students’ direct mentorship, we just couldn’t offer the undergraduates this type of hands-on involvement.”
Ultimately, Hugenberg hopes that his team’s work may help us better understand the processes by which certain individuals or groups of people become dehumanized by others.
“Instead of asking what makes a face seem human,” Hugenberg says, “we could ask what makes a person seem no longer like a person. When that happens, social cognition is essentially turned off, and it stops us from being motivated to think of people as people.”
Insofar as that mechanism for dehumanization helps explain slavery, genocide, and other atrocities, Hugenberg’s research may help lead us closer to a world in which all people are safe and valued.
Written by Heather Beattey Johnston, Associate Director & Information Coordinator, Office for the Advancement of Research & Scholarship, Miami University.