Because allostasis is a predictive system, it can be influenced or miscalibrated by early life stressors or extreme traumas. A stable fetal and early childhood environment can lead to a well-functioning allostatic system. But adverse childhood experiences can result in a system that either overreacts or just shuts down in response to what might otherwise be considered normal daily ups and downs, creating hypervigilance, reduced resilience, and sometimes wild mood swings—a lifetime in which normal allostatic regulation is never reached.
