4C A biological model of stress

General adaptation syndrome (GAS)

A biological model of stress that proposes we have a non-specific biological response to stress that occurs in three stages

Alarm reaction stage

The first stage of the general adaptation syndrome, in which we become aware of the stressor; it consists of two phases - shock and countershock.

Shock

The first phase of the alarm reaction of the general adaptation syndrome, in which the body's ability to deal with the stressor falls below normal. The body reacts as if it was injured ( eg. blood pressure and body temperature drop)

Countershock

The second phase of the alarm reaction stage of the general adaptation syndrome, in which the body's ability to deal with the stressor rises above normal. When the body rebounds, the sympathetic nervous system is activated, initiating the flight-fight-freeze responds, high arousal and increased energy

Resistance stage

The second stage of the general adaptation syndrome, in which the stressor persists, and the body's resources are maximised to cope and adapt over time. Physiological processes that don’t strengthen resistance can slow or temporarily hate ( e.g. digestion, sex drive, menstruation). Cortisol is released into the bloodstream to further increase energy and help repair any bodily damage.

Exhaustion stage

The third stage of the general adaptation syndrome, in which the continued depletion of energy stores, and high levels of hormones such as cortisol decrease resistance to the stressor and impair the immune system. The body’s resources become depleted, the immune system is suppressed one becomes vulnerable to physical and mental illness.

Strengths of Selye’s GAS

• Theory suggests the link between stress and they body’s vulnerability to illness.

• Identifies biological processes (hormone secretion and immune suppression) associated with the body’s stress response.

• The model suggests a predictable pattern that can be tested in a laboratory.

Weaknesses of Selye’s GAS

• It assumes that everyone has the same predictable physiological response to any kind of stressor. Not every individuals experiences the same physical response to stress (e.g. gaining or losing weight)

• Humans and rats are physiologically different

• Does not take into account the cognitive aspects of the stress response (appraisal of a situation)