Biological Dynamics of Stress Responses: Understanding Fight, Flight, and Freeze Behaviour in Humans

Abstract

Human responses to threat are regulated by integrated biological systems that support rapid adaptation and survival. This study examines the biological dynamics of the fight, flight, and freeze responses, focusing on neural, autonomic, and endocrine mechanisms. The paper reviews the roles of the amygdala in threat perception, the hypothalamus in activating physiological responses, and the prefrontal cortex in behavioural regulation. It further explains the involvement of the autonomic nervous system and the hypothalamic–pituitary–adrenal axis, highlighting the functions of adrenaline and cortisol in stress activation. A conceptual proportional model is presented to illustrate the distribution of fight, flight, and freeze responses in contemporary psychological contexts. The study also discusses the cognitive and emotional effects of prolonged stress, including its influence on attention, memory, and emotional regulation. Additionally, the role of neuroplasticity in modifying stress responses through psychological interventions is highlighted. The findings provide a structured understanding of stress-related behaviour and offer implications for counselling psychology and therapeutic practice.