Study Shows How the Brain Works While Speaking To Someone of a Different Social Class

The human brain apparently responds differently whenever we talk to someone of a different socioeconomic background from our own, compared to when we speak to someone we perceive as from a similar background, according to a new study.

Researchers from the University College London (UCL) and Yale University have conducted a new imaging study. They monitored 39 pairs of participants talking to each other, with each correspondent wearing a headset that monitored their brain activity. Details of their research are published in the journal Social Cognitive and Affective Neuroscience.

Brain Response to Socioeconomic Disparity

The study was conducted to inquire about an emerging theoretical framework suggesting that frontal lobe networks are behind judgment related to stereotyping and prejudice. This part of the brain supposedly helps us manage our behavior to avoid expressing bias, as well as detecting bias from other people.

Socioeconomic backgrounds of the participants were computed by the researchers based on educational attainment and annual household income. Researchers assigned points on pre-defined strata on education and income, classifying 19 pairs as "high disparity" and 20 pairs as "low disparity."

They used functional near-infrared spectrometry (fNIRS) as the participants engaged in a face-to-face live communication session. As the participants talked to their partners in-study, the fNIRS monitors their blood flow and oxygen levels from near-infrared light level changes. The participants in the study only had to wear a device similar to a headset, contrary to previous beliefs. They detected MRI scans unadvisable for conversation as it would have required participants to lie down and keep still.

Conversation between pairs lasted for about 12 minutes and involved random topics like "How do you bake a cake?" or "What did you do last summer?"

Identifying Neural Mechanisms of The Socioeconomic Social Interactions

Researchers discovered that the people who came from very different socioeconomic backgrounds, exhibited increased levels of brain activity in a specific part of the frontal lobe, known as the left dorsolateral prefrontal cortex. This area is often linked with speech production, following rule-based language, cognition, and managing attention.

After the monitored conversation, participants were asked to accomplish a questionnaire. Again, participants who had to talk to people of different backgrounds reported higher levels of anxiety and effort in maintaining the conversation.

"For the first time, we have identified the neural mechanisms involved in social interactions between people of different backgrounds," said professor Joy Hirsch, from the Yale School of Medicine and UCL Department of Medical Physics and Biomedical Engineering.

She also believed that their findings offer a "hopeful message," adding how humans can have positive social encounters with different people. Hirsch also noted that their study had produced the neurobiological basis that our brains have developed its frontal lobe system to help deal with diversity.

Olivia Descorbeth, Yale College undergraduate and lead author of the study, came up with the researcher study as her proposal. "We wanted to know if the brain responded differently when we talked to others of a different socioeconomic background," Descorbeth said. "Now we know that it does and that humans have neurobiology that helps us navigate social differences."