The phenomenon you're describing

The phenomenon described is called sensory adaptation or habituation, specifically social desensitization or adaptive numbing.It develops as a protective response to repeated exposure to uncomfortable or threatening social stimuli, especially for minority groups or those with visible differences.The brain's threat detection system, mainly in the amygdala, initially reacts strongly but gradually filters social threats as background noise through neurological pathways like the reticular activating system.This adaptation helps individuals function in hostile environments by reducing stress responses and hypervigilance.However, it can also dampen social sensitivity, making it harder to detect important social cues or engage fully in positive interactions.The same neural pathways that filter out threats may also reduce sensitivity to friendly gestures, reflecting how systemic prejudice impacts social perception.