Stress and Emotion for the MCAT: Everything You Need to Know

Master MCAT stress and emotion concepts with clear explanations of stress responses, emotion theories, coping mechanisms, and high-yield practice questions.

(Note: This guide is part of our MCAT Psychology and Sociology series. )

Table of Contents

Part 1: Introduction to stress and emotion

Part 2: Stress 

a) Origins of stress

b) Physiological response

c) Managing stress

Part 3: Emotion

a) Roles of emotion

b) Theories of emotion

c) Biological components

Part 4: High-Yield Terms

Part 5: Passage-Based Questions and Answers

Part 6: Standalone Questions and Answers

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Part 1: Introduction to stress and emotion

Emotion and stress are high-yield topics that will earn you significant points on the Psychology/Sociology section of the MCAT. This guide will give you a thorough understanding of the physiological and behavioral reactions that human beings experience.

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Part 2: Stress

Stress is a feeling in response to a disconcerting situation. However, it is an experience that is far more difficult to communicate with others. It is also important to remember that stress is usually caused by combinations of environmental factors and thus can usually be controlled through lifestyle management. 

Stress itself can be categorized as distress, which causes negative emotions, or eustress, which causes positive emotions. Examples of eustress include exercising to release endorphins or spending time on a creative or artistic project.

a) Origins of stress

Stress is the result of a stressor, which is a distressing stimulus or event. A stress reaction is a person’s response to the stressor.

Our appraisal is the way that we interpret the stressor. Primary appraisal refers to our interpretation of the immediate stressor—for instance, the recognition of a car speeding toward a pedestrian—and our determination of the threat, while secondary appraisal is the assessment of actions that can be taken in response to the stressor.

There are three main types of stressors: daily stressors, life events, and catastrophic events.

• Daily stressors are minor hassles in everyday life, such as interpersonal disputes or financial stress

• Life events are significant changes in one’s personal life, like moving houses or the death of a loved one

• Catastrophic events are large-scale happenings that are outside of an individual’s control, such as natural disasters or wars. 

Each of these types of stressors causes a reaction in the person experiencing them but varies in acuity and intensity.

b) Physiological response

Physiological response to a stressor is primarily driven by the autonomic nervous system.

The autonomic nervous system is broken down into two main components: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system is responsible for our “fight-or-flight” response. This response prompts an endocrine response in which the adrenal medulla releases the hormones epinephrine and norepinephrine. These hormones prompt an increase in heart rate, blood flow to the skeletal muscles, and other responses that prime the body for quick action. In response, the adrenal cortex also releases cortisol, a steroid hormone that suppresses the immune system and utilizes energy from fat instead of glucose. Though our bodies can handle short-term stress, chronic stress can lead to hypertension (high blood pressure), an impaired immune system, and damaged reproduction in women. 

In contrast, the parasympathetic nervous system is responsible for our “rest-and-digest” state. When the body is at rest, this system makes the digestive system more active and reduces blood flow to skeletal muscles. 

The Yerkes-Dodson Law states that elevated levels of stress and arousal improve performance up to a point. However, beyond the optimal point of arousal, our performance decreases. The distribution of performance by arousal follows a bell-shaped curve. 

Figure 1    The Yerkes-Dodson law states that we exhibit peak performance when experiencing average arousal and stimulation.

According to the Yerkes-Dodson Law, mild stress can actually improve psychological functioning and increase motivation. A prime example is the focus that individuals can harness during important exams. However, a high level of stress impairs psychological functioning by causing loss of concentration, anxiety, and exhaustion. 

c) Managing stress

On the emotional front, high levels of stress can lead to anhedonia, a diminished ability to experience pleasure, and one of the symptoms of depression and anxiety. Major stress events can also cause post-traumatic stress disorder. Furthermore, chronic stress brings about learned helplessness, where a person feels a lack of control over the outcomes of their life due to repeated stressful events.

Behaviorally, there are many different responses to stress that one person can have. One common reaction is to feel anxious and resort to avoidance of the stressor. Another is to turn to addiction in the form of tobacco, drugs, or alcohol. However, depending on the magnitude of the stressor and its potential for harm, individuals oftentimes decide to handle the stressor directly.

There are several ways to handle stress. The MCAT primarily focuses on three solutions: exercise, relaxation, and spirituality. 

The first is exercise, which decreases the risk of cardiovascular disease and lowers blood pressure. Aerobic exercise can also aid in reducing depression symptoms by releasing hormones like serotonin and endorphins. The second is relaxation. Techniques like meditation slow breathing and controlling heart rate can be effective in reducing stress levels. Finally, spirituality has been found to aid in mitigating stress. Having faith beliefs is correlated with being healthier. Furthermore, faith communities provide social support, which allows for better processing of stressful situations and can dissipate personal burdens. 

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Part 3: Emotion

a) Roles of emotion

Emotions are subjective experiences we have in response to internal or external stimuli. There are three components of emotion: (1) physiological, (2) cognitive, and (3) behavioral responses to a stimulus. While the physiological component refers to the body’s physical response to a stimulus, the cognitive component is the “thinking” facet of a stimulus response or the mental assessment of a situation. The behavioral component refers to the external expression or response to a stimulus. 

Why do we express emotions? Darwin theorized that it was evolutionarily advantageous for human beings to be able to both express and understand emotions, a theory known as the adaptive role of emotion. In other words, people who could express and understand emotions increased their chances of survival and reproduction. Thus, modern-day humans possess these characteristics as well.

As a result, there are some facial expressions, known as universal emotions, that most people, regardless of culture, language, or country of origin, can recognize. These emotions—fear, anger, sadness, disgust, happiness, and surprise—are all characterized by different anglings of the eyebrows, mouth, and wrinkles in the face. These emotions are so universally recognized by humans that the inability to recognize emotions is often diagnosed as a symptom of psychological disorder.

b) Theories of emotion

While our facial displays of emotion may be universally comprehensible, it is unclear how we process stimuli in our environment and formulate emotional responses. There are three key competing theories on how we encode and, ultimately, experience emotions in response to a stimulus. These are definitely high-yield concepts to know!

• The James-Lange theory argues that our body’s physiological response to a stimulus, in addition to our subsequent perception of that response, is what makes us feel emotion. 

• The Cannon-Bard theory states that our body’s physiological response to a stimulus and our cognitive experience of emotion occur simultaneously but independently. 

• The Schacter-Singer theory, or the two-factor theory, states that our emotional experiences are caused by the cognitive interpretation of our body’s physiological responses to the specific situation we are in.

Each of these theories was proposed as an alternative to the previous one, and while there is no universal consensus on a single “correct” theory, it is important that you familiarize yourself with the commonalities and differences between these three theories. 

c) Biological components

The nervous system is responsible for both processing the environmental stimuli into perception and for sending signals to display and communicate emotion. The limbic system of the brain is responsible for our experiences of emotion and comprises many different structures, each of which has a distinct function. 

At the center of the limbic system is the amygdala, an almond-shaped structure within the brain that conducts our emotional experiences and communicates with the hypothalamus. While the amygdala is integral to our emotions of fear and aggression, the hypothalamus controls our physiological response to a stimulus through the autonomic nervous system. The autonomic nervous system is especially important in emotions pertaining to fear and survival and is thus key in the physiological response to stress. (We will expand on this later in the guide.)

Additionally, the thalamus is our brain’s sensory relay center and sends information to other parts of the brain to be processed. The hippocampus contributes to emotional processing by encoding the emotions that we associate with our memories. 

Lastly, the prefrontal cortex is responsible for our executive functions, so it controls how we respond to emotional experiences. More simply put, it is where we make higher-level decisions and inhibit our impulses.

There are several physiological markers of emotion, which are related to the functioning of the autonomic nervous system. For intense emotions like anger or surprise, there can be increased heart rate, perspiration, elevated blood pressure, and increased skin temperature. Tears and crying are perhaps the most obvious physical marker of emotion and are a result of sadness or, on other happier occasions, joy.

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Part 4: High-yield terms

Emotions: subjective experiences that we have as the result of an internal or external stimulus

Components of emotion: the physiological, cognitive, and behavioral responses to a stimulus

Adaptive role of emotion: Darwin’s theory that it is evolutionarily advantageous for human beings to be able to both express and understand emotions

Universal emotions: facial expressions that people across all countries and cultures can recognize; includes fear, anger, sadness, disgust, happiness, and surprise

James-Lange theory: the body’s physiological response to a stimulus and our subsequent perception of that response is what makes us feel emotion

Cannon-Bard theory: the body’s physiological response and experience of emotion happening simultaneously but independently 

Schacter-Singer theory: emotional experience is the result of our body’s physiological response being interpreted cognitively based on the specific situation we are in

Limbic system: the system of the brain responsible for our experience of emotion

Amygdala: brain structure that conducts our emotional experiences and is integral to fear and aggression

Hypothalamus: brain structure that hypothalamus controls our physiological response to a stimulus through the autonomic nervous system

Autonomic nervous system: component of the peripheral nervous system that is responsible for our automatic physiological responses

Thalamus: our brain’s sensory processing center that sends information to other parts of the brain. 

Hippocampus: brain structure that contributes to emotional processing by encoding the emotions that we associate with our memories. 

Prefrontal cortex: brain structure responsible for our executive functions

Executive functions: the brain’s capacity for higher-level decision making

Sympathetic nervous system: responsible for our “fight-or-flight” reaction

Parasympathetic nervous system: responsible for our “rest-and-digest” state

Yerkes-Dodson Law: elevated levels of arousal improve performance up to a point, but past that optimal point, performance decreases

Stress: a feeling in response to a disconcerting situation

Stressor: a distressing stimulus or event

Stress reaction: a person’s response to the stressor

Appraisal: how we interpret the stressor

Primary appraisal: our interpretation of the immediate stressor

Secondary appraisal: our assessment of actions to take in response to the stressor

Daily stressor: minor hassles in everyday life

Life events: significant changes in one’s personal life

Catastrophic events: large scale happenings that are outside of an individual’s control

Endocrine response: release of epinephrine and norepinephrine by the adrenal medulla in response to a dangerous threat

Cortisol: steroid hormone that suppresses the immune system and utilizes energy from fat instead of glucose

Anhedonia: diminished ability to experience pleasure 

Learned helplessness: when a person feels no control over the outcomes of their life because of repeated stressful events

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Part 5: Passage-based questions and answers

Physiological arousal can serve to improve or impair individual performance on certain tasks, depending on the extent of arousal and the nature of the task. Researchers investigate the effect of physiological arousal on memory. A memory recognition task was implemented, in which study participants were initially presented with 30 different words on a computer screen. Later, participants were presented with another 30 words and asked to identify if each word was or was not present in the initial stage. Many of the words presented in the later stage were similar to the initial words. For example, the word “walkway” could appear in the initial stage, while a related word (“crosswalk”) could appear in the later stage. However, several words were repeated without alteration from the initial stage.

In the experimental condition, participants were presented with the initial 30 words, then led down a hallway. In this hallway, an actor purposefully intimidated the study participant by leaping around the approaching corner. The participant was immediately directed into another room and given the recognition task. In the control condition, participants were taken down the same hallway and into the other room without being surprised. 

All study participants were given a heart rate monitor to wear for the duration of the study. The number of errors committed on the recognition task by each participant is shown in Figure 1.

Figure 1    Resulting number of errors and changes in heart rate on the recognition task

Question 1: Which brain structure was most closely associated with participants’ immediate response to surprise in the experimental condition?

A) Prefrontal cortex

B) Thalamus

C) Amygdala

D) Hippocampus

Question 2: In this study, the dependent variable is the:

A) Number of errors committed

B) Change in heart rate

C) Surprise attack

D) Physiological arousal

Question 3: The trend in the data from the experimental condition can be best explained by which phenomenon?

A) Cannon-Bard theory

B) Yerkes-Dodson Law

C) Endocrine response

D) Learned helplessness

Question 4: Which physiological response were participants least likely to have after the surprise in the experimental condition?

A) Muscle fatigue

B) Perspiration

C) Decreased digestion

D) Increased blood flow

Question 5: Suppose researchers conducted another experimental condition where participants were led in brief meditative exercises that lowered their heart rates before completing the final stage of the recognition task. Under this condition, participants were found to make more errors on average than control participants. How would this new data affect the results of the study?

A) Supports; heightened arousal causes more errors

B) Supports; the further away from optimal arousal, the more errors will occur

C) Refutes; lower heart rates should correspond to fewer errors on average

D) Refutes; this shows that there is no relationship between heart rate and memory

Answer key for practice passage

1. Answer choice C is correct. The amygdala is most closely associated with fear and aggression. Therefore, it would be most involved in the initially frightened response of participants to the surprise (choice C is correct). The prefrontal cortex is involved in our executive functions (choice A is incorrect), while the thalamus relays information to different parts of the brain (choice B is incorrect). The hippocampus encodes emotions associated with memories (choice D is incorrect).

2. Answer choice A is correct. The dependent variable is a measurement that varies based on the manipulation of the independent variable. In this study, the independent variable is the change in heart rate (choice A is correct). While elevated heart rate is one component of physiological arousal, it does not represent all stimulated components of the sympathetic or parasympathetic nervous system (choice D is incorrect). According to Figure 1, the dependent variable is the number of errors committed (choice B is incorrect). The “surprise attack” is an element of the experimental condition (choice C is incorrect).

3. Answer choice B is correct. The Yerkes-Dodson Law states that elevated arousal can increase performance up to a certain point. With additional arousal or stress, performance is then impaired. From the data, we can see that the fewest errors occur around a change in heart rate of 30 bpm, and to either side of that, the number of errors increases (choice b is correct). The Cannon-Bard theory explains we experience emotion (choice A is incorrect), while the endocrine response is our body’s physiological response to a threat (choice C is incorrect). Learned helplessness is feeling a lack of control due to repeated stressful events with unfavorable outcomes (choice D is incorrect).

4. Answer choice A is correct. The sympathetic nervous system is responsible for our “fight-or-flight” response to danger, which includes increased heart rate, perspiration, increased blood flow to skeletal muscles, and inhibited digestion (choices B, C, and D are incorrect). Muscle fatigue is not involved in the initial “fight-or-flight” response (choice A is correct).

5. Answer choice B is correct. According to the Yerkes-Dodson Law, there is an optimal level of arousal where performance is maximized, and the further from this point (decreased or heightened arousal) one gets, the lower their performance will be (choice B is correct). According to Figure 1, this optimal level of stress is concurrent with a heart rate of 30 bpm. Lowering heart rates beyond this point should cause more error and thus refute the study (choices C and D are incorrect). The experimental condition in this study does not address heightened arousal (choice A is incorrect).

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Part 6: Practice standalone questions and answers

Question 1: Which of the following is not a component of emotion?

A) Cognitive 

B) Physiological

C) Psychological 

D) Behavioral

Question 2: Which hormone is released during the body’s endocrine response?

A) Testosterone

B) Insulin

C) Aldosterone

D) Norepinephrine

Question 3: Which theory of emotion is also known as the “two-factor theory”?

A) Schacter-Singer theory

B) Cannon-Bard theory

C) James-Lange theory

D) Yerkes-Dodson law

Question 4: A camper opens her tent and sees a bear rummaging through her belongings. The camper’s evaluation of the threat that the bear poses is part of:

A) Primary appraisal

B) Secondary appraisal

C) Stress reaction

D) Universal emotion

Question 5: Anhedonia is best described as:

A) A lack of motivation

B) Trouble falling asleep

C) Feeling a lack of control

D) Diminished ability to experience pleasure

Answer key for standalone questions

1. Answer choice C is correct. The three components of emotion are physiological, cognitive, and behavioral responses to a stimulus (choices A, B, and D are incorrect). Psychological response is not a component of emotion. 

2. Answer choice D is correct. In the endocrine response, the adrenal medulla releases epinephrine and norepinephrine (choice D is correct), and the adrenal cortex releases cortisol. Testosterone, insulin, and aldosterone are not released in the “fight-or-flight” response. 

3. Answer choice A is correct. The Schacter-Singer theory is also known as the “two-factor theory” because it posits that emotional experience is the result of a physiological response to a stimulus being interpreted cognitively depending on the situation (choice A is correct). The Cannon-Bard theory states that the body’s physiological response and our experience of emotion happen simultaneously (choice B is incorrect). The James-Lange theory states that the body’s physiological response and our subsequent perception of that response make us feel emotion (choice C is incorrect). The Yerkes-Dodson Law discusses the effect of arousal on performance (choice D is incorrect).

4. Answer choice A is correct. Primary appraisal is an evaluation of the harm that a stressor poses (choice A is correct). Secondary appraisal refers to an evaluation of the resources that are available to address any immediate threat (choice B is incorrect). A stress reaction is a person’s response to a stressor (choice C is incorrect). Universal emotions refer to a set of facial expressions that can be interpreted across all cultures (choice D is incorrect). 

5. Answer choice D is correct. Anhedonia is defined as a diminished ability to experience pleasure—it is a common symptom of anxiety and depression and a result of chronic stress.