A small University of California study suggests that we are hard-wired to process – or not process – facial differences based on race at some of the earliest stages of sensory perception.
You often hear it framed in a comic sense, though it’s a form of stereotyping, and even prejudice. “You all look alike to me.” To one race, the tired adage implies, people in other races are tough to differentiate from each other. Some call it the “other-race effect.”
It’s something more than a wince-worthy punchline. New University of California – Riverside research bears it out, finding we are hard-wired to process – or not process – facial differences based on race. And that process occurs in the earliest filters of our thought process.
The research was led by UC Riverside psychologist Brent Hughes. The overriding question posited in the paper: When we observe members of another racial group, are their actual physical distinctions blurred in our mind’s eye?
The study participants were 17 white people studying white and black faces on a monitor while lying inside a functional MRI scanner, which identifies changes in brain activity. Some experiments were also conducted outside of the MRI.
Hughes and his team looked at the white participants’ high-level visual cortex to see whether it was more tuned in to differences in white faces than black ones. The visual cortex is the first stop for processing impulses from the eyes; the high-level visual cortex specialising in processing faces.
Their findings affirmed previous studies, determining that participants showed a greater tendency to individuate – recognise differences in – own-race faces, and less for other races. But Hughes’ study went further, demonstrating how deep this tendency runs: as far as our earliest sensory processes. “Our results suggest that biases for other-race faces emerge at some of the earliest stages of sensory perception,” Hughes wrote.
Hughes wrote that the fallout from noticing the differences in members of one own’s race but not others is profound. These early perceptions can cascade, affecting downstream beliefs and behaviours. The implications can range from embarrassing to life-changing – think of when the wrong suspect in a crime is selected from a line-up. “We are much more likely to generalise negative experiences if we see individuals as similar or interchangeable parts of a broad social group,” Hughes said.
Previous studies have found the “other-race effect” is found in populations other than whites. But Hughes isn’t comfortable extending his findings to assume that black people also “de-individuate” white faces in the high-visual visual cortex. The reason: Majority vs minority perceptions.
“Members of minority groups wind up being exposed to more members of majority groups than majority members get exposed to minority members,” he said. “It could be that exposure to individuals of different groups may help the visual system develop expertise that reduces this effect.”
The study shouldn’t be interpreted as a pass for “you all look the same to me,” Hughes said.
“These effects are not uncontrollable,” he said. “These race biases in perception are malleable and subject to individual motivations and goals. In this sense, attitudes, motives and goals can be shaping visual perceptual processes.”
Co-authors in the study include Nicholas P Camp, Jennifer L Eberhardt, Vaidehi S Natu, and Kalanit Grill-Spector of Stanford University; and Jesse Gomez of University of California – Berkeley.
A hallmark of intergroup biases is the tendency to individuate members of one’s own group but process members of other groups categorically. While the consequences of these biases for stereotyping and discrimination are well-documented, their early perceptual underpinnings remain less understood. Here, we investigated the neural mechanisms of this effect by testing whether high-level visual cortex is differentially tuned in its sensitivity to variation in own-race versus other-race faces. Using a functional MRI adaptation paradigm, we measured White participants’ habituation to blocks of White and Black faces that parametrically varied in their groupwise similarity. Participants showed a greater tendency to individuate own-race faces in perception, showing both greater release from adaptation to unique identities and increased sensitivity in the adaptation response to physical difference among faces. These group differences emerge in the tuning of early face-selective cortex and mirror behavioral differences in the memory and perception of own- versus other-race faces. Our results suggest that biases for other-race faces emerge at some of the earliest stages of sensory perception.
Brent L Hughes, Nicholas P Camp, Jesse Gomez, Vaidehi S Natu, Kalanit Grill-Spector, Jennifer L Eberhard