General Adaptation Syndrome (GAS) is Hans Selye's model describing the body's physiological response to stress in three stages: alarm reaction, resistance, and exhaustion.
General Adaptation Syndrome (GAS) is Hans Selye's three-stage model of how your body physically responds to a stressor. The key idea: your body reacts to stress in the same general pattern no matter what's causing it, whether it's an exam, an injury, or a breakup.
The three stages go in order. Alarm reaction is the initial jolt, your fight-or-flight response kicks in, heart rate spikes, and stress hormones flood your system. Resistance is when your body settles into a high-alert state and tries to cope while the stressor sticks around. Exhaustion hits if the stress drags on too long, your resources run dry and you become vulnerable to illness, fatigue, and burnout. Selye's focus is on the biological side of stress, which is why it slots into the biological half of the biopsychosocial picture.
GAS lives in Topic 7.4 (Stress and Coping), part of the Health Psychology content. It's the go-to model for explaining the body's physiological stress response, and the AP exam loves to pair it with cognitive models that focus on how you perceive stress instead. Knowing GAS lets you explain why chronic stress wears down the body over time, which connects directly to how stress affects the immune system and overall health.
Cognitive Appraisal Theory (Unit 7)
GAS is the body's automatic biological response; cognitive appraisal is about how your mind sizes up a situation as threatening or manageable. The exam often contrasts these two: one is physiological and stage-based, the other is all about perception and evaluation.
Alarm Reaction, Resistance Stage, and Exhaustion Stage (Unit 7)
These aren't separate concepts, they're literally the three stages of GAS. Learn them as a sequence: the alarm fires, the body resists, and if stress never lets up, exhaustion sets in.
Biopsychosocial Model (Unit 7)
GAS is the 'bio' piece in action. It shows how a physical stress response feeds into health, while psychological and social factors shape how badly that stress hits you.
On multiple-choice questions, you'll often see GAS tied to its author (Hans Selye) and asked to identify it as the physiological stress response, or to put the three stages in the correct order. A common trap pairs it against cognitive appraisal, where you have to pick the model that says stress comes from your perception of a situation rather than a fixed bodily pattern. You may also see a twist on the assumption that chronic stress always wrecks the immune system, since some research challenges that. On the FRQ side, a 2018 SAQ asked about high school student stress levels, the kind of applied scenario where understanding the body's stress stages helps you reason about the effects of stress on health.
GAS is biological and automatic, your body cycles through alarm, resistance, and exhaustion no matter what you're thinking. Cognitive appraisal theory is psychological: stress depends on how you interpret a situation, so the same event can stress out one person and not another. If a question emphasizes perception or evaluation, it's appraisal; if it emphasizes physical stages, it's GAS.
General Adaptation Syndrome was proposed by Hans Selye to describe the body's physiological response to stress.
GAS has three stages in order: alarm reaction, resistance, and exhaustion.
GAS treats the stress response as a general pattern that's the same regardless of the specific stressor.
It's the biological model of stress, contrasted on the exam with cognitive appraisal theory, which focuses on perception.
Reaching the exhaustion stage from chronic stress can leave the body vulnerable to illness, though some research questions whether chronic stress always damages the immune system.
It's Hans Selye's model of the body's physiological response to stress, which happens in three stages: alarm reaction, resistance, and exhaustion. It's covered in Topic 7.4, Stress and Coping.
Hans Selye proposed GAS. The exam frequently asks you to connect the model directly to his name.
Alarm reaction (the initial fight-or-flight jolt), resistance (sustained high alert while coping), and exhaustion (resources run out and you become vulnerable to illness). Getting the order right matters on MCQs.
GAS is biological and automatic, the body moves through the same stages regardless of the stressor. Cognitive appraisal theory is psychological, where stress depends on how you perceive and evaluate the situation. If a question stresses perception, it's appraisal, not GAS.
Not necessarily. While reaching the exhaustion stage can leave you vulnerable to illness, some research suggests chronic stress doesn't automatically lead to immune system deterioration, an alternative viewpoint the exam may test.