Nadine Burke Harris

The biological memory of forgotten trauma Many adults dismiss early childhood adversity because they lack conscious memory of the events. Dr. Nadine Burke Harris argues that the opposite is true: the younger the child, the more profound the impact on the biological stress response. While the mind may not store a narrative of infancy, the body maintains a cellular record. This biological imprint dictates how a person handles pressure decades later, transforming early environmental signals into permanent physiological settings. Cross-fostering reveals the power of nurture Research involving rat populations provides a striking look at how caregiving influences genetic expression. In studies where baby rats were stressed and then returned to their mothers, those who received "buffering" care—licking and grooming—showed significantly higher stress tolerance. Conversely, rats deprived of this care suffered from prolonged stress hormone activation long after the threat vanished. The most radical finding occurred during cross-fostering: babies born to low-buffering mothers who were raised by high-buffering mothers adopted the stress resilience of their adoptive parent, not their biological one. Epigenetic markers override genetic blueprints This research proves that experience actually rewires how DNA is read. The The Mel Robbins Podcast highlights that epigenetic markers—the chemical tags that turn genes on or off—are shaped by early caregiving. When a child receives consistent buffering, it changes the way their DNA expresses itself, leading to better cognitive performance and emotional regulation. This shift isn't just behavioral; it is a physical restructuring of the nervous system's operating manual. Breaking the cycle of inherited stress Because these biological settings are often passed from parent to child through behavior, trauma can feel like an inherited destiny. However, the plasticity shown in cross-fostering studies offers hope. By understanding that the stress response is a wired system rather than a fixed personality trait, individuals can begin the work of intentional regulation. Recognizing that a "fired up" nervous system is a physiological relic of the past is the first step toward reclaiming emotional control.