Fading affect bias

Biological Parallel

Prey animals that survive attacks retain threat awareness but emotional intensity fades—persistent terror would prevent foraging and reproduction. Rodents exposed to predator cues show PTSD-like responses (hyperarousal, exaggerated fear, avoidance) that persist for 3 months, yet gradually habituate enough to resume foraging in risky areas while maintaining heightened vigilance. Plains zebras that survive lion attacks return to grazing near waterholes—the same locations where predators hunt—within days, balancing learned caution with survival imperatives. Impalas witnessing herd mate kills show immediate stress responses, but within hours resume normal feeding patterns while avoiding the specific kill site. The brain preserves factual memory ('that location is dangerous') while decoupling it from paralyzing emotion over time. Fading affect is emotional homeostasis: keeping the lesson while releasing the suffering allows organisms to function after trauma without forgetting what caused it.