The medial prefrontal cortex is involved in helping establish ingroup and outgroup. Dr. Eagleman detailed in his PBS series on the brain that the medial prefrontal cortex is less active for many people when seeing photographs of the homeless because there is less connection to them.[i] The brain is shut off to their pain as if they have less existence or worth. This is the tragedy of indifference. The humanity of the other is lost just as our own humanity is lost. Love is lost.
Not extending love to others who are different from us is central to prejudice. There are several parts of the brain associated with prejudice. The amygdala involves our association with threats. As the mind creates and maintains understanding of threats, our ideas can become reinforced. The anterior insula involves the process of negative affect. The medial prefrontal cortex (mPFC) helps put things in perspective and bring them into a mental picture. While the mPFC helps us categorize the world, the downside is that our categorizations can be completely false though they seem real to us. The truth is that a person without a home has as much worth and is worthy of our love as any other person.
All these structures taken together help categorize ingroup and outgroup.[ii] Positive attitudes toward an ingroup are supported by the striatum. Within cultural contexts, when we are told to believe stereotypes and prejudice, the neural circuitry to perpetuate hate gets strengthened and then passed on to the next generation. Sadly, prejudice can be either conscious or unconscious. Many people who are full of hate might not realize there is another way because of how they were raised or taught. Our theology helps ground us in the reality that we are all interconnected. We are to love God with all our hearts and love our neighbors as ourselves. When we break down the walls of in-group and out-group perceived in the world, we help restructure our brains. This includes the medial prefrontal cortex.
[i] “The Brain with David Eagleman, Episode 5, ‘Why Do I Need You?’,” PBS, accessed October 1, 2019, https://www.pbs.org/video/brain-david-eagleman-why-do-i-need-you-episode-5/.
[ii] “The Neuroscience of Prejudice and Stereotyping,” ResearchGate, accessed July 10, 2018, https://www.researchgate.net/publication/265345113_The_Neuroscience_of_Prejudice_and_Stereotyping.