How our brains respond to race changes as we develop from children to adolescents, according to a new study on race perception. The researchers found that a child’s social environment plays an important role in developing neural bias to race. The more diversity we are surrounded by at a young age, the less a person’s race seems to matter in the brain as we develop into young adults.
Past research has found that infants as young as 3 to 6 months old can discriminate between racial groups, and from preschool age, children can accurately identify a person’s racial group membership. However, scientists have yet to understand when this sorting becomes “a more meaningful social category,” says Eva Telzer of the University of Illinois at Urbana-Champaign.
To better understand these process, Telzer and her colleagues looked to the amygdala, the brain region involved in processing environmental stimuli that people find emotional based on previous experience. Previous research has shown heightened response in the amygdala to African American faces among adults. To test when this response emerges in youth, the researchers used used fMRI to measure the responses of children and adolescents, ranging in age from 4 to 16 years old, to African American and European faces. “Our study is the first to examine the neurodevelopment of race perceptions in children across a wide age range,” says Telzer, whose team conducted the work in Nim Tottenham’s Developmental Affective Neuroscience lab at the University of California, Los Angeles.
The research team found that the amygdala becomes increasingly sensitive to African American faces across development, with a significant response only emerging at age 14 years. This response, the researchers say, likely is the result of developmental processes in which the amygdala acquires emotional knowledge learned over time – perhaps the result of implicit and explicit cultural stereotypes or perhaps also the result of the increased social importance of race as children enter adolescence. For example, when students begin high school, they may join ethnic clubs to explore their identity.
The researches also tested social influences on the neural response to race by looking at how study participants’ exposure to peer diversity in their neighborhoods correlated to their amygdala response. When children have more cross-race friends and schoolmates, they were less likely to exhibit a neural bias to African American faces, they found. “These findings suggest that we should pay careful attention to the environment, in this case peer diversity, when understanding the development of differential perceptions and how the brain responds to social stimuli,” Telzer says.
The study opens many questions about exactly when in development homogeneity versus diversity shapes racial perceptions. Telzer’s team hopes to further understand how experience changes the amygdala response to race and group membership.
-Lisa M.P. Munoz
The paper “Amygdala Sensitivity to Race Is Not Present in Childhood but Emerges over Adolescence,” Eva H. Telzer, Kathryn L. Humphreys, Mor Shapiro, and Nim Tottenham, was published in the Journal of Cognitive Neuroscience, online on October 15, 2012.
Media contact: Lisa M.P. Munoz, CNS Public Information Officer, firstname.lastname@example.org