[WORLD] A question as old as humanity itself—why do we help others?—is being re-examined through the lens of neuroscience by an international team of researchers. Their latest findings, published in the Proceedings of the National Academy of Sciences (PNAS), identify a key region in the brain that may underpin prosocial behavior.
At the center of this inquiry is the basolateral amygdala, a structure deep within the limbic system. This brain region appears to play a pivotal role in shaping how we relate to those around us.
Thanks to recent advances in neuroimaging, scientists are now able to map the amygdala’s complex networks with exceptional precision. These maps reveal that the basolateral amygdala is far from isolated—it maintains active communication with the prefrontal cortex, an area known for decision-making and impulse regulation. This neural dialogue suggests that acts of altruism may result from a finely tuned balance between emotional response and rational evaluation.
The study, led by Professor Tobias Kalenscher of Heinrich Heine University in Düsseldorf, was carried out in collaboration with institutions in Lausanne, Utrecht, and Cape Town. It focused on a rare neurological disorder: Urbach-Wiethe disease.
This genetic condition specifically damages the basolateral amygdala, while sparing other parts of the brain. Caused by mutations in the ECM1 gene, the disorder leads to calcium deposits in the skin and brain. While its physical symptoms—such as skin lesions and hoarseness—are well documented, its psychological and social effects are less understood.
Researchers chose to conduct the study in Namaqualand, a remote region of South Africa, where the condition is unusually prevalent. The area’s close-knit community and high concentration of Urbach-Wiethe cases offered a unique opportunity to observe how brain differences influence social behavior in a natural setting.
To investigate, scientists employed a method familiar to behavioral economists: the “dictator game.” In this experiment, participants are given money and must decide how much, if any, to give to another person—whether a family member, neighbor, or stranger.
The outcomes were revealing. Individuals with Urbach-Wiethe syndrome displayed typical levels of generosity toward close relations. However, their willingness to share dropped significantly when interacting with less familiar individuals.
This pattern suggests a disruption in the brain’s ability to scale social behavior based on emotional closeness. It aligns with prior studies showing the amygdala’s role in assessing threat and emotional salience—abilities thought to underpin social risk-taking, such as generosity toward strangers.
“Individuals with BLA damage were just as generous toward people they were close to as healthy control participants,” said Luca M. Lüpken, a doctoral candidate and co-author of the study. “However, as soon as it came to individuals with whom they had less of an emotional connection, they were notably more selfish.”
The findings underscore the amygdala’s regulatory function: not as a direct source of generosity, but as a modulator that helps determine to whom generosity is extended. When this function is impaired, social behaviors can become more self-serving.
Such insights may also shed light on neuropsychiatric conditions—like autism or psychopathy—where deviations from typical social behavior are common. Understanding the neural mechanisms that govern altruism could eventually lead to interventions aimed at restoring social functioning.
For Professor Kalenscher, the implications are far-reaching: “Social decisions are not only shaped by our upbringing or culture. They are in fact also strongly anchored in the mechanisms of our brain,” he noted.
This growing understanding of the biological roots of altruism offers not only potential therapeutic avenues but also a deeper reflection on the foundations of a compassionate and inclusive society.
WhatsApp
Instagram
Threads
