EMOTION, STRESS and HEALTH

Imagine trying to list all the emotions you feel during a day. You might include frightened, angry, sad, joyful, disgusted, worried, bored, ashamed, frustrated, awed, contemptuous, embarrassed, surprised, proud, and confused. But which of those states are really emotions? And how many are different emotions instead of overlapping or synonymous conditions?

Defining the term emotion is difficult. Psychologists usually define it in terms of a combination of cognition's, physiology, feelings, and actions (Keltner & Shiota, 2003; Plutchik, 1982). For example, you might have the cognition "he was unfair to me," physiological changes that include increased heart rate, a feeling you call anger, and behaviors such as a clenched fist. However, that definition implies that cognitions, physiology, feelings, and actions always occur together. Do they? Or might you sometimes feel frightened without knowing why, or experience anger without taking any action?

In fact, it is debatable whether emotion is a natural category at all. Lisa Feldman Barrett (2012) has argued that emotions are a category that we find useful, but only in the same way that we find "weeds" to be a useful category. Nature does not distinguish between emotions and motivations any more than between flowers and weeds.

Measuring Emotions

Research progress depends on good measurement. Psychologists measure emotions by self-reports, behavioral observations, and physiological measures. Each method has its strengths and weaknesses.

Self-Reports

Psychologists most often measure emotions by asking people how happy they g are, how nervous, and so forth. Self-reports are quick and easy, but their accuracy is limited. If you rated your happiness 4 yesterday and 7 today, it seems clear & that vou have become happier. But if you rate your happiness 7 and your friend rates her happiness 6, are you happier than she is? Maybe, maybe not.

Behavioral Observations

We infer emotion from people's behavior and its context. If we see someone shriek and run away, we infer fear. When you were an infant, your parents must have inferred your emotions before you could report them verbally. They had to, in order to teach you the words for emotions! At some point, you screamed, and someone said you were "afraid." At another time, you smiled, and someone said you were "happy." Behavioral observations are often a better indicator than self-reports are. If you see someone making a fist, screaming, and frowning, while insisting, "I'm not angry," which do you believe, the observations or the words?

Observing the face is sometimes helpful. People control many expressions voluntarily, but sudden, brief emotional expressions, called microexpressions, are harder to control. For example, someone who is pretending to be calm or happy may show occasional brief signs of anger, fear, or sadness (Ekman, 2001). With practice, or a videotape that can be played slowly, psychologists infer emotions that people would like to hide. Still, it is an uncertain inference, as people's expressions do not always match what they feel. Ordinarily, an emotional state elicits a tendency toward vigorous action, even if we suppress that tendency. Here, a soldier disarms a mine.

Physiological Measures

Originally, the term emotion referred to turbulent motion. Centuries ago, people described thunder as an "emotion of the atmosphere. Eventually, people limited the term to body motions and their associated feelings, but the idea still includes turbulent arousal. Any stimulus that arouses emotion alters the activity of the autonomic nervous system, the section of the nervous system that controls the organs such as the heart and intestines. (See Figure 3.25.) The autonomic nervous system consists of the sympathetic and the parasympathetic nervous systems. Chains of neuron clusters just to the left and right of the spinal cord comprise the sympathetic nervous system, which arouses the body for vigorous action. It is often called the "fight-or-flight" system because it increases heart rate, breathing rate, sweating, and flow of epinephrine (EP-i-NEF-rin; also known as adrenaline), thereby preparing the body for vigorous activity.

The parasympathetic nervous system consists of neurons whose axons extend from the medulla and the lower part of the spinal cord to neuron clusters near the organs. The parasympathetic nervous system decreases the heart rate and promotes digestion and other nonemergency functions. Both the sympathetic and parasympathetic systems send axons to the heart, the digestive system, and most other organs. The adrenal gland, sweat glands, and muscles controlling blood vessels and "goosebumps" receive only sympathetic input.

Both systems are constantly active, although one system can temporarily dominate. If you spot danger at a distance (in either time or space), you pay attention to it with mainly parasympathetic activity. If the danger is close enough to require action, you shift to vigorous sympathetic activity (Löw, Lang, Smith, & Bradley, 2008). Many situations activate parts of both systems (Berntson, Cacioppo, & Quigley, 1993). For example, some emergency situations increase your heart rate and sweating (sympathetic responses) and also promote bowel and bladder evacuation (parasympathetic responses). Have you ever been so frightened that you thought you might lose your bladder control?

To measure emotion, researchers measure sympathetic nervous system arousal as indicated by heart rate, breathing rate, or momentary changes in the electrical conductivity across the skin. However, remember that the sympathetic nervous system is the fight-or-flight system, so its responses could indicate anger, fear, or any other intense emotion, as well as nonemotional influences such as exercise. Physiological measurements never tell us which emotion someone is feeling.